@article{2baecdd053f8412a8cd0043acce2ba1f, title = "Additive manufacturing of monolithic supercapacitors with biopolymer separator", abstract = "In this paper, additive layer-by-layer fabrication of a fully screen printed monolithic supercapacitor exhibiting performance comparable with supercapacitors prepared using lamination is reported. A novel separator material improves the performance of the monolithic supercapacitor, is easily applicable using scalable processes such as screen and stencil printing, and is based on sustainable biomaterials. The additive monolithic manufacturing offers advantages for system integration and avoids the need of an additional alignment step as needed in the fabrication of laminated supercapacitors. Previously, the monolithically fabricated supercapacitors showed higher equivalent series resistance (ESR) and leakage current than the laminated ones. By using microfibrillated cellulose (MFC) and chitosan as separator materials ESR and leakage current were decreased. These disposable and non-toxic aqueous electrolyte supercapacitors are optimized for autonomous sensor systems, for example in Internet-of-Things (IoT) applications, with capacitance of 200–300 mF and ESR of about 10 Ω. The new composite separator material consisting of MFC and chitosan has good adhesion on the electrodes and the substrate, is easy to apply using printing and coating processes, and does not diffuse into the porous electrode. Graphic Abstract: [Figure not available: see fulltext.].", keywords = "Chitosan, Energy storage, MFC, Microfibrillated cellulose, Nanocellulose, Printed electronics, Separator, Supercapacitors", author = "Maedeh Arvani and Jari Keskinen and Anna Railanmaa and Sanna Siljander and Tomas Bj{\"o}rkqvist and Sampo Tuukkanen and Donald Lupo", year = "2020", month = "6", day = "1", doi = "10.1007/s10800-020-01423-2", language = "English", volume = "50", pages = "689--697", journal = "Journal of Applied Electrochemistry", issn = "0021-891X", publisher = "Springer Verlag", number = "6", }
@article{380046174ca648c79360624852f6f419, title = "A study of Cr3C2-based HVOF- and HVAF-sprayed coatings: Abrasion, dry particle erosion and cavitation erosion resistance", abstract = "Material and spray process selection are the key factors in the tailoring of thermal sprayed coatings for demanding industrial applications. In this study, four commercial Cr3C2-based feedstock materials were sprayed with gas-fuelled high-velocity oxygen-fuel (HVOF) and modern high-velocity air-fuel (HVAF) spray processes. Two materials with standard Cr3C2–25NiCr composition (porous and dense), a Cr3C2–50NiCrMoNb and Cr3C2–37WC–18NiCoCr materials were sprayed in addition to the reference WC-10Co4Cr material. The Cr3C2–50NiCrMoNb had a higher content of the Ni-based metal matrix compared to standard Cr3C2–25NiCr composition for added corrosion resistance, while the Cr3C2–37WC–18NiCoCr material contained additional tungsten carbide (WC) particles to improve the wear resistance. In abrasion and dry particle erosion, the Cr3C2–50NiCrMoNb coatings showed a higher degree of plastic deformation and increased material loss, whereas the Cr3C2–37WC–18NiCoCr coating had wear resistance between the standard Cr3C2–25NiCr and reference WC-10Co4Cr coatings. In cavitation erosion, the lower carbide content of Cr3C2–50NiCrMoNb coatings turned out to improve the resistance against fatigue wear due to higher fracture toughness. Overall, the HVAF sprayed coatings had higher elastic modulus, higher fracture toughness, equal or higher abrasion and erosion resistance, and higher cavitation erosion resistance compared to the HVOF sprayed counterparts.", keywords = "Abrasion, Cavitation erosion, Coating, Erosion, Hardmetal, HVAF", author = "V. Matikainen and H. Koivuluoto and P. Vuoristo", year = "2020", month = "4", day = "15", doi = "10.1016/j.wear.2020.203188", language = "English", volume = "446-447", journal = "Wear", issn = "0043-1648", publisher = "Elsevier", }
@article{9202281a6f8c40b3a39ca4c6c1f84372, title = "Structure and in vitro dissolution of Mg and Sr containing borosilicate bioactive glasses for bone tissue engineering", abstract = "Borosilicate bioactive glasses are promising for bone tissue engineering. The objective was to assess the impact of magnesium and/or strontium, when substituted for calcium on the glasses' thermal and dissolution properties. Both Mg and Sr substitution appeared to enhance the hot forming domain, i.e. the ability to hot process (sinter, draw fibres) without adverse crystallization. Structural analysis indicated that substitution of MgO and/or SrO for CaO results in changes in the BO3/BO4 ratio as well as in the ratio between bridging and non-bridging oxygen atoms in the silicate structure. Additionally, a de-shielding effect was noticed when Ca, Mg and Sr are present together in the glass network, possibly owing to PO4 3− charge-balanced preferentially by Na+. The Mg and/or Sr substitution resulted in a lower ion release in simulated body fluid and delayed formation of hydroxyapatite. However, once this layer formed it consisted of a Mg/Sr-substituted apatite. This work highlights the effect of combined ionic substitutions on bioactive glass structure and properties.", keywords = "Bioactive glasses, Borosilicate glasses, In vitro dissolution, Structural properties, Tissue engineering", author = "Tainio, {J. M.} and Salazar, {D. A.Avila} and A. Nommeots-Nomm and C. Roiland and B. Bureau and Neuville, {D. R.} and Brauer, {D. S.} and J. Massera", year = "2020", month = "4", day = "1", doi = "10.1016/j.jnoncrysol.2020.119893", language = "English", volume = "533", journal = "Journal of Non-Crystalline Solids", issn = "0022-3093", publisher = "Elsevier", }
@article{d92b24ffdc7f4161ac1ed8df6ce1fdc8, title = "Transparent Yb3+ doped phosphate glass-ceramics", abstract = "Yb3+ doped oxyfluorophosphate glasses with the composition (98.75) [90NaPO3-(10-x) Na2O-xNaF] - 1.25Yb2O3 (in mol{\%}) with x = 0, 2.5, 5, 7.5 and 10 were prepared using a standard melting process. The progressive replacement of Na2O by NaF leads to an increase in the number of Q2 units at the expense of the Q1 units. This increase in the polymerization of the glass network leads to a shift of the optical band gap to lower wavelength, to a slight increase in the intensity of the emission at 1000 nm and more importantly to a change in the glass crystallization process. Indeed, both surface and bulk crystallization were observed in the glass with x = 0 while surface crystallization only occurs when NaF is added in the phosphate network. The heat treatment leads to the precipitation of at least three crystalline phases: as x increases, the NaPO3 phase grows at the expense of Na5P3O10. All glasses precipitate the Yb containing crystal, NaYbP2O7 which leads to an increase in the intensity of the emission at 1000 nm compared to the emission at 975 nm. We show for the first time to the best of our knowledge that transparent Yb3+ doped phosphate glass-ceramics can be obtained within this glass system when free of NaF.", keywords = "Glass-ceramic, Luminescence, Phosphate glass, XRD, Yb", author = "M. Hongisto and A. Veber and Boetti, {N. G.} and S. Danto and V. Jubera and L. Petit", year = "2020", month = "1", day = "1", doi = "10.1016/j.ceramint.2020.01.121", language = "English", journal = "Ceramics International", issn = "0272-8842", publisher = "Elsevier", }
@article{ef761e70f606491abc4c2ca971141f35, title = "Cold gas spraying of a high-entropy CrFeNiMn equiatomic alloy", abstract = "Cold gas spraying was used to make a coating from an equiatomic CrFeNiMn high-entropy alloy. This four-component alloy was chosen because it is Co-free, thus allowing application in nuclear industries as a possible replacement of currently used stainless steel coatings. The feedstock material was gas atomized powder with a particle size distribution from 20 to 45 μm. A number of parameters were tested, such as the powder feed rate and gas feed pressure, in order to obtain as dense a coating as possible with nitrogen as the process gas. Spraying was performed using a gas preheating temperature of 1000 °C, gas feed pressure ranging from 50 to 60 bar, and two powder feeding rates. The coating thicknesses ranging from 230 to 490 m and porosities ranging from 3{\%} to 10{\%} were obtained depending on the powder feed rate and gas feed pressure. The hardness of the cross-section of the coating was usually lower than that of the surface. The highest coating hardness obtained was above 300 HV0.3 for both the surface and the cross-section. The as-atomized powder consisted of a face-centered cubic (FCC) phase with a minute amount of body-centered cubic (BCC) phase, which was no longer detectable in the coatings. The microstructure of the coating was highly stressed due to the high degree of deformation occurring in cold gas spraying. The deformation leads to strain hardening and induces a pronounced texture in the coating. The 111 planes tend to align along the coating surface, with deformation and texturing concentrating mainly on particle boundaries. A high-entropy alloy (HEA) coating was successfully sprayed for the first time using nitrogen as a process gas. The coating has the potential to replace stainless steel coatings in nuclear industry applications.", keywords = "Cold gas spraying, High-entropy alloy, Microstructure", author = "Joonas Lehtonen and Heli Koivuluoto and Yanling Ge and Aapo Juselius and Hannula, {Simo Pekka}", year = "2020", doi = "10.3390/coatings10010053", language = "English", volume = "10", journal = "Coatings", issn = "2079-6412", publisher = "MDPI", number = "1", }
@article{2b377254fc3e41b1b1e5cc696e35e416, title = "Compounding and characterization of recycled multilayer plastic films", abstract = "Mechanical recycling of multilayer plastic films from food packages was investigated. The multilayer films were manually separated from municipal solid waste, washed, grinded, and finally compounded at 0–100 wt{\%} concentrations with virgin low-density polyethylene (PE-LD). Polyethylene grafted with maleic anhydride (PE-g-MA) compatibilizer was used in two of the compounds to replace 2 and 5 wt{\%} of the PE-LD to study its effect as well. PE-g-MA is expected to improve the mechanical properties of the compounds by promoting the adhesion between incompatible polymer phases. The composition of the compounds was characterized with Fourier-transform infrared spectroscopy and differential scanning calorimetry and their properties were studied with tensile testing and rotational rheometer measurements. All tested compounds had relatively good mechanical properties and processability. This indicates that recycled multilayer films could replace at least part of the virgin PE-LD in applications where high-thermal stability or good visual appearance is not required. The PE-g-MA compatibilizer did not have a significant effect on the mechanical properties of the compounds.", keywords = "mechanical properties, recycling, rheology, thermal properties, thermoplastics", author = "Ilari J{\"o}nkk{\"a}ri and Valeria Poliakova and Ville Myll{\"a}ri and Reetta Anderson and Mirja Andersson and Jyrki Vuorinen", year = "2020", doi = "10.1002/app.49101", language = "English", journal = "Journal of Applied Polymer Science", issn = "0021-8995", publisher = "Wiley", }
@article{9e7bca75d348417d8a3fd2c65c1d9c2f, title = "Electronic transport in n-type modulation-doped AlGaAs/GaAsBi quantum well structures: Influence of Bi and thermal annealing on electron effective mass and electron mobility", abstract = "We investigate electronic transport properties of as-grown and annealed n-type modulation-doped Al0.15Ga0.85As/GaAs1-xBix (x = 0 and 0.04) quantum well (QW) structures using magnetotransport measurements in the temperature range 4.2 K and 60 K and at magnetic fields up to 18 T. Thermal annealing process was applied at two different temperatures, 700 °C and 350 °C during 60 s and 180 s, respectively. We find that electron effective mass and 2D electron density in as-grown Bi-containing sample are slightly lower than that in Bi-free one. Furthermore, quantum electron mobility and quantum scattering time are observed to be decreased in Bi-containing samples. The annealing process at 700 °C causes a slight increase in electron effective mass and 2D electron density. A negligible decrease in electron effective mass and an increase in 2D electron density are determined following annealing at 350 °C. The observed change in electron effective mass following thermal annealing process is attributed to changing 2D electron density in the samples. No improvement on quantum electron mobility and quantum scattering time are observed following thermal annealing at both process temperatures. We determine that one electron subband (e1) for as-grown and annealed (at 700 °C for 60 s) Bi-containing QWs and two electron subbands (e1 and e2) for the annealed (at 350 °C for 180 s) GaAsBi QW sample and the Bi-free QW sample contribute to electronic transport. Our results reveal that there is no significant direct effect of Bi on effective electron mass, but an indirect effect, in which Bi can provoke changes in 2D electron density and hence causes not to observe actual band-edge electron mass but a deviation from its band-edge value. Therefore, it can be concluded that dispersion curve of conduction band does not change as an effect of Bi incorporation in GaAs.", keywords = "bismuthindependent effective mass, Electron effective mass in GaAsBi, electron mobility in GaAsBi, electronic transport in GaAsBi, n-type GaAsBi", author = "O. Donmez and M. Aydin and Ardali and S. Yildirim and E. Tiraş and F. Nutku and C. Cetinkaya and E. okduygulular and J. Puustinen and J. Hilska and M. Guina and A. Erol", year = "2020", doi = "10.1088/1361-6641/ab5d8d", language = "English", volume = "35", journal = "Semiconductor Science and Technology", issn = "0268-1242", publisher = "IOP Publishing", number = "2", }
@article{9700162adbfd4be7b8e4525000e9ec80, title = "Influence of powder properties on residual stresses formed in high-pressure liquid fuel HVOF sprayed WC-CoCr coatings", abstract = "This paper presents a systematic study of the effect of various WC-CoCr powders on the residual stresses of the high pressure HVOF sprayed coating. As the residual stresses are recognized to play a significant role in the mechanical and fatigue resistance of the coating, it is understandable that their management is important for damage tolerant coating design. Several studies have recently shown that processes, which produce high particle kinetic energy and lower particle temperature, such as Warm spray, HVAF and high-pressure HVOF processes, generate higher peening stresses and therefore final residual stresses is more compressive compared to lower kinetic energy HVOF systems. In addition to the spraying process, powder properties are known to be one of the most important variables in thermal spraying. Nevertheless, only few studies can be found on the effect of powder properties on residual stresses. The aim of this study was to understand the effect of different powder properties on the formation of residual stress. In situ monitoring was utilized to record curvature and temperature during spraying and to calculate coating residual stresses. This approach is a useful tool for understanding of residual stresses during the thermal spraying process enabling their manipulation. It was found that the powders, with only minor differences in density and particle size, produced a significant difference of about 350 MPa in the stress states of the coatings. The combined effect of spray powder properties and spray parameters on residual stress was almost 560 MPa.", keywords = "Agglomerated powder, Apparent density, High pressure HVOF, Residual stress, Thermal spraying, WC-CoCr", author = "Tommi Varis and Tomi Suhonen and Mika Jokipii and Petri Vuoristo", year = "2020", doi = "10.1016/j.surfcoat.2020.125604", language = "English", volume = "388", journal = "Surface & Coatings Technology", issn = "0257-8972", publisher = "Elsevier", }
@article{5feb515ee46246d3a97b555f2542e459, title = "Effect of tempering on the impact-abrasive and abrasive wear resistance of ultra-high strength steels", abstract = "Tempering is an essential part in the fabrication of ultra-high strength steels and it is also widely applied in the processing of wear-resistant steels. In this paper, the effects of different tempering temperatures on the impact-abrasive and abrasive wear properties of martensitic ultra-high strength steels were studied. A novel press-hardening steel with carbon content of 0.4 wt{\%} was received in hot-rolled condition and further austenitized, water-quenched and tempered for 2 h at different temperatures (150–400 °C). Tensile strength values up to 2200MPa and hardness exceeding 650HV were measured. Wear testing was done with impact-abrasive impeller-tumbler and abrasive dry-pot application-oriented test methods simulating mining and mineral handling environments. A laboratory rolled 600HB steel and a commercial 500HB grade wear-resistant steel were included for comparison. The wear surfaces and cross-sections of the samples were thoroughly characterized. Both testing methods produced highly deformed surface layers and strong work-hardening. Wear performance was mainly controlled by the initial hardness of the steels, but differences were found in the highly work-hardened surfaces of the steels.", keywords = "Abrasion, Impact-abrasion, Steel, Tempering, Wear testing", author = "Oskari Haiko and Kati Valtonen and Antti Kaijalainen and Sampo Uusikallio and Jaakko Hannula and Tommi Liimatainen and Jukka K{\"o}mi", year = "2019", month = "12", day = "15", doi = "10.1016/j.wear.2019.203098", language = "English", volume = "440-441", journal = "Wear", issn = "0043-1648", publisher = "Elsevier", }
@article{a371764b938642bfb9d7aa4c4331eba4, title = "First principles prediction of the solar cell efficiency of chalcopyrite materials AgMX2(M=In, Al; X=S, Se, Te)", abstract = "Using the spectroscopic limited maximum efficiency, and Shockley and Queisser predictor models, we compute the solar efficiency of the chalcopyrites AgMX 2 (M = In, Al; X = S, Se, Te). The results presented are based on the estimation of the electronic and optical properties obtained from first principles density functional theory as well as the many-body perturbation theory calculations. The results from this report were consistent with the experimental data.The optical bandgap was accurately estimated from the absorption spectra, obtained by solving the Bethe and Salpeter equation. Fitting the Tauc's plot on the absorption spectra, we also predicted that the materials studied have a direct allowed optical transition. The theoretical estimations of the solar cell performance showed that the efficiencies from the Shockley and Queisser model are higher than those from the spectroscopic limited maximum efficiency model. This improvement is attributed to the absorption, the recombination processes and the optical transition accounted in the calculation of the efficiency.", keywords = "Chalcopyrites, First principles, Solar cell efficiency", author = "Dongho-Nguimdo, {G. M.} and Emmanuel Igumbor and Serges Zambou and Joubert, {Daniel P.}", year = "2019", month = "12", day = "1", doi = "10.1016/j.cocom.2019.e00391", language = "English", volume = "21", journal = "Computational Condensed Matter", issn = "2352-2143", publisher = "Elsevier BV", }
@article{f73faa630d4f402982e7d5b372cdbd28, title = "Porous polybutylene succinate films enabling adhesion of human embryonic stem cell-derived retinal pigment epithelial cells (hESC-RPE)", abstract = "In the last decade, several studies have shown that polybutylene succinate (PBSu)has a high potential as a biomaterial enabling cell adhesion and growth. In this study, porous PBSu films have been prepared by the breath figure method (BF)and by particulate leaching (PL), and characterized in terms of thickness, surface properties, diffusion capacity and in vitro stability. Because porous films are of high interest for tissue engineering of retinal pigment epithelium (RPE), the initial viability and adhesion of human embryonic stem cell-derived RPE onto the PBSu films was then evaluated. To the best of our knowledge, this is the first study on the adhesion behavior of hESC-RPE onto porous and biodegradable polymer surfaces. The results clearly demonstrated that the two manufacturing methods produced materials with very distinct properties. Films produced by BF expressively demonstrated the highest roughness and surface area, and the lowest water contact angle. These features likely contributed to increase the biocompatibility of the surface, particularly when coated with laminin and collagen IV, as observed by the improved cell viability, cell morphology, adhesion and production of extracellular matrix proteins. Altogether, our results showed not only that PBSu holds high potential in retinal tissue engineering, but also that the physical properties and biocompatibility of the material are highly dependent on the adopted casting method.", keywords = "Biodegradable films, Breath figures, Cell adhesion, Polybutylene succinate, Retinal pigment epithelium", author = "Calejo, {M. Teresa} and Anne Haapala and Heli Skottman and Minna Kellom{\"a}ki", year = "2019", month = "9", day = "1", doi = "10.1016/j.eurpolymj.2019.05.041", language = "English", volume = "118", pages = "78--87", journal = "European Polymer Jounal", issn = "0014-3057", publisher = "Elsevier", }
@article{ba0750799070427ca3b8a0b579fc4633, title = "Antibacterial polymer fibres by rosin compounding and melt-spinning", abstract = "The antibacterial features of natural pine/spruce rosin are well established, yet the functionality in various thermoplastics has not been surveyed. This work focuses on the processing of industrial grade purified rosin mixed with polyethylene (PE), polypropylene (PP), polylactic acid (PLA), polyamide (PA)and corn starch based biopolymer (CS). Homopolymer masterbatches were extrusion-compounded and melt-spun to form fibres for a wide range of products, such as filters, reinforcements, clothing and medical textiles. Due to the versatile chemical structure of rosin, it was observed compatible with all the selected polymers. In general, the rosin-blended systems were shear-thinning in a molten condition. The doped fibres spun of PE and PP indicated adequate melt-spinning capability and proper mechanical properties in terms of ultimate strength and Young's modulus. The antibacterial response was found dependent on the selected polymer. Especially PE with a 10 wt{\%} rosin content showed significant antibacterial effects against Escherichia coli DH5α and Staphylococcus aureus ATCC 12598 when analysed in the Ringer's solution for 24 h.", keywords = "Antibacterial, Fibre, Melt spinning, Thermoplastics", author = "M. Kanerva and A. Puolakka and Takala, {T. M.} and Elert, {A. M.} and V. Myll{\"a}ri and I. J{\"o}nkk{\"a}ri and E. Sarlin and J. Seitsonen and J. Ruokolainen and P. Saris and J. Vuorinen", note = "EXT={"}Myll{\"a}ri, V.{"}", year = "2019", month = "9", doi = "10.1016/j.mtcomm.2019.05.003", language = "English", volume = "20", journal = "Materials Today Communications", issn = "2352-4928", publisher = "Elsevier BV", }
@article{0ed7445d18ff4f92bea46f2164915d8a, title = "Detection of gaseous species during KCl-induced high-temperature corrosion by the means of CPFAAS and CI-APi-TOF", abstract = "Two different analytical approaches—collinear photofragmentation and atomic absorption spectroscopy (CPFAAS) and chemical ionization atmospheric pressure interface time-of-flight mass spectrometer (CI-APi-TOF)—were applied to detect and identify the online gaseous KOH and HCl formed in the addressed high-temperature reactions. Samples of pure KCl, KCl+Cr, KCl+Fe, and KCl+316 L were studied at 550°C under dry and humid conditions with varying oxygen concentrations. The goal was to shed more light on the gas-phase chemistry during KCl-induced corrosion under conditions relevant to biomass combustion. CI-APi-TOF proved to be a valuable tool for high-temperature corrosion studies: HCl was identified to have formed during the reactions under humid conditions. On the contrary, despite the known sensitivity of CPFAAS, the formation of KOH could not be verified in any of the performed measurements.", keywords = "CI-APi-TOF, CPFAAS, gaseous KCl, HCl formation, high-temperature corrosion", author = "Juho Lehmusto and Miska Olin and Jan Viljanen and Joni Kalliokoski and Fanni Myll{\"a}ri and Juha Toivonen and {Dal Maso}, Miikka and Leena Hupa", year = "2019", month = "8", day = "30", doi = "10.1002/maco.201910964", language = "English", journal = "Materials and Corrosion-Werkstoffe und Korrosion", issn = "0947-5117", publisher = "Wiley-VCH Verlag", }
@article{577fd8207da641b5926da1d0e26b92bf, title = "Characterizing the micro-impact fatigue behavior of APS and HVOF-sprayed ceramic coatings", abstract = "The fatigue life of thermally sprayed Al2O3- and Cr2O3-based coatings has been studied under low-energy (0.7–5 mJ) impact conditions. A threshold impact energy and amount of repetitions the coatings can endure with said energy before catastrophic failure was obtained. The catastrophic failure was determined to occur when the fracture mode of the coating switched from brittle cone cracking to quasi-plastic radial cracking. The results are examined relative to the microstructural features along with other properties of the coatings - hardness and cavitation resistance. The experiment provided a new approach for a straightforward comparison of the micro-scale impact fatigue life of thermally sprayed coatings unachievable with previous methods.", keywords = "Ceramic coating, Characterization, Fracture, Impact test, Surface fatigue, Thermal spray", author = "J. Kiilakoski and C{\'e}cile Langlade and H. Koivuluoto and P. Vuoristo", year = "2019", month = "8", day = "15", doi = "10.1016/j.surfcoat.2018.10.097", language = "English", volume = "371", pages = "245--254", journal = "Surface & Coatings Technology", issn = "0257-8972", publisher = "Elsevier", }
@article{c5603bffeca841b6b63a43a60bbefe74, title = "Fluorine losses in Er3+oxyfluoride phosphate glasses and glass-ceramics", abstract = "Er 3+ doped phosphate glasses with the composition 75NaPO 3- 25CaF 2 (mol{\%})were prepared at different melting temperatures to demonstrate the importance to quantify the fluorine content when preparing oxyfluoride glasses. Indeed, increasing the melting temperature from 900 to 1000 °C leads to a small reduction in the fluorine content from 9.4 at {\%} to 8.8 at {\%} as quantified using EPMA. Whereas this loss of fluorine can be suspected from small changes in the thermal properties of the glass, it increases significantly the glass crystallization tendency in this glass system. This means that a heat treatment of the as-prepared glass should be performed when evaporation of fluorine during the glass melting is suspected. Sample preparation for the characterization of the spectroscopic properties of the glasses is discussed here as well; bulk glasses should be used when measuring the spectroscopic properties of oxyfluoride glasses, which are known to be hygroscopic. It is shown, in this work, that a heat treatment of the glass within the investigated glass system leads to transparent glass-ceramics with volume precipitation of Er 3+ doped CaF 2 crystals with strong upconversion.", keywords = "Crystal, Erbium, Fluorine, Glass, Glass-ceramic, Luminescence", author = "A. Szczodra and A. Mardoukhi and M. Hokka and Boetti, {N. G.} and L. Petit", year = "2019", month = "8", day = "15", doi = "10.1016/j.jallcom.2019.05.151", language = "English", volume = "797", pages = "797--803", journal = "Journal of Alloys and Compounds", issn = "0925-8388", publisher = "Elsevier", }
@article{301a177849c94065b3c6af03da1c1616, title = "Modelling thermodynamics in a high erature superconducting dipole magnet: An inverse problem based approach", abstract = "The use of practical high temperature superconductors (HTS), REBCO tapes especially, in magnet applications has become possible thanks to the increasing interest of manufacturers. One difficulty has been the nonlinear material properties that are challenging to measure and model. To advance in such, demo systems are needed and they must be thoroughly analyzed. Recently, one of the first HTS dipole magnets was built to study the usability of REBCO Roebel cables in particle accelerator magnets. The prototype magnet Feather-M2 was designed, constructed and tested within EUCARD2 collaboration project at CERN in 2017. In the measurements, the magnet behaved in an unexpected way: the magnet was able to be operated at operation currents above the maximum current that was predicted based on short-sample measurements. Additionally, unexpectedly gradual dependency between magnet's resistive voltage and operation current was observed. In this work, a thermodynamical model is formulated in order to study the behavior of Feather-M2. The model was parametrized and the parameters were solved via inverse problem by finding the best match to experimental results. Thereby insight was gained on the prospects of the utilized thermodynamical model and also on the behavior and operation conditions of the magnet via the inverse problem solutions. To summarize, this paper presents a new methodology for analyzing magnets in operation and applies it to a state-of-the-art magnet.", keywords = "HTS magnets, modelling, optimization, thermal stability", author = "J. Ruuskanen and A. Stenvall and V. Lahtinen and Nugteren, {J. Van} and G. Kirby and J. Murtom{\"a}ki", year = "2019", month = "8", day = "2", doi = "10.1088/1361-6668/ab2bc9", language = "English", volume = "32", journal = "Superconductor Science and Technology", issn = "0953-2048", publisher = "IOP Publishing", number = "9", }
@article{bc8a7fa83e374c36b814af3d5d516916, title = "Erosion wear performance of WC-10Co4Cr and Cr3C2-25NiCr coatings sprayed with high-velocity thermal spray processes", abstract = "Thermally sprayed hardmetal coatings are widely used to protect components and surfaces against wear in various applications. Hard and wear resistant coatings increase the component lifetime and can generate significant savings promoting ecological manufacturing. This study focuses on the performance of tungsten carbide (WC-10Co4Cr)and chromium carbide (Cr 3 C 2 -25NiCr)based hardmetal coatings sprayed with gaseous and liquid fuelled high-velocity oxygen-fuel (HVOF)spray processes and a modern high-velocity air-fuel (HVAF)spray process. The coating characterisation revealed reduced carbide dissolution with decreasing process temperature and denser feedstock powder particles. Smaller carbide size in the Cr 3 C 2 -25NiCr material significantly reduced the carbide rebounding leading to higher carbide content in the sprayed coating and improved erosion wear resistance. Most significant improvements were observed in cavitation erosion for HVAF sprayed WC-10Co4Cr coatings (0.4 μm/h)compared to the HVOF sprayed coatings (1.5–3.7 μm/h). The cavitation erosion resistance of the HVAF sprayed coatings was almost at the level of the WC-10Co sintered bulk (0.2 μm/h).", keywords = "Cavitation erosion, Coating, Hardmetal, Slurry erosion, Thermal spray", author = "V. Matikainen and {Rubio Peregrina}, S. and N. Ojala and H. Koivuluoto and J. Schubert and Houdkov{\'a} and P. Vuoristo", note = "INT=msee,{"}Rubio Peregrina, S.{"}", year = "2019", month = "7", day = "25", doi = "10.1016/j.surfcoat.2019.04.067", language = "English", volume = "370", pages = "196--212", journal = "Surface & Coatings Technology", issn = "0257-8972", publisher = "Elsevier", }
@article{854e4e4fdbfd420c9d39a5da87fe6f0b, title = "Water-Responsive and Mechanically Adaptive Natural Rubber Composites by in Situ Modification of Mineral Filler Structures", abstract = "A new biomimetic stimuli-responsive adaptive elastomeric material, whose mechanical properties are altered by a water treatment is reported in this paper. This material is a calcium sulphate (CaSO4) filled composite with an epoxidized natural rubber (ENR) matrix. By exploiting various phase transformation processes that arise when CaSO4 is hydrated, several different crystal structures of CaSO4·xH2O can be developed in the cross-linked ENR matrix. Significant improvements in the mechanical and thermal properties are then observed in the water-treated composites. When compared with the untreated sample, there is approximately 100{\%} increase in the dynamic modulus. The thermal stability of the composites is also improved by increasing the maximum degradation rate temperature by about 20 °C. This change in behavior results from an in situ development of hydrated crystal structures of the nanosized CaSO4 particles in the ENR matrix, which has been verified using Raman spectroscopy, transmission electron microscopy, atomic force microscopy, and X-ray scattering. This work provides a promising and relatively simple pathway for the development of next generation of mechanically adaptive elastomeric materials by an eco-friendly route, which may eventually also be developed into an innovative biodegradable and biocompatible smart polymeric material.", author = "Banerjee, {Shib Shankar} and Sakrit Hait and Natarajan, {Tamil Selvan} and Sven Wie{\ss}ner and St{\"o}ckelhuber, {Klaus Werner} and Dieter Jehnichen and Andreas Janke and Dieter Fischer and Gert Heinrich and Busfield, {James J.C.} and Amit Das", year = "2019", month = "6", day = "20", doi = "10.1021/acs.jpcb.9b02125", language = "English", volume = "123", pages = "5168--5175", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "24", }
@article{5eee811b271249849b98e156710129be, title = "Epitaxial phases of high Bi content GaSbBi alloys", abstract = "GaSbBi alloys have recently emerged as attractive materials for mid-infrared optoelectronics owing to strong band gap reduction enabled by Bi incorporation into the GaSb matrix. The fundamental understanding of the epitaxial process required to demonstrate high quality crystals is in an early-developmental phase. From this perspective, we report on the key role played by the Sb/Ga flux ratio in controlling the structural quality and incorporation of high Bi content GaSbBi (up to 14.5{\%}-Bi), revealing three distinct epitaxial phases. The first phase (below stoichiometric Sb/Ga) exhibits Ga-Bi compound droplets, low crystal quality, and reduced Bi content. At the second phase (above stoichiometric Sb/Ga), the crystal exhibits smooth surfaces and excellent crystallinity with efficient Bi incorporation. The last phase corresponds to exceeding a Sb/Ga threshold that leads to reduced Bi incorporation, Bi droplets and degraded crystallinity. This threshold value that defines the optimal growth window is controlled by the temperature as well as the Bi/Ga ratio. Increasing temperature increases the threshold, albeit simultaneously reducing Bi incorporation. Conversely, increasing the Bi/Ga flux ratio increases Bi incorporation, while narrowing down and ultimately closing the window. This study provides a general framework enabling development of high quality GaSbBi heterostructures for emerging mid-infrared optoelectronics.", keywords = "A3. Molecular beam epitaxy, B1. Antimonides, B1. Bismuth compounds, B2. Semiconducting III-V materials, B2. Semiconducting ternary compounds", author = "Joonas Hilska and Eero Koivusalo and Janne Puustinen and Soile Suomalainen and Mircea Guina", year = "2019", month = "6", day = "15", doi = "10.1016/j.jcrysgro.2019.03.028", language = "English", volume = "516", pages = "67--71", journal = "Journal of Crystal Growth", issn = "0022-0248", publisher = "Elsevier", }
@article{780e01ad6ae7476eb92fabe15350c63a, title = "Role of fracture toughness in impact-abrasion wear", abstract = "Two new low alloyed steels were developed with different fracture toughness values but at similar level of hardness with same composition and microstructural phase. The steels were subjected to impact-abrasion wear test. This work examines specifically the additional role of toughness during impact-abrasion wear, using a newly developed high toughness steel. Microstructural characterisation of the damaged samples revealed that better toughness helps resist both impact and abrasion damage.", keywords = "Abrasion, Fracture toughness, Impact-abrasion, Steel, Wear testing", author = "Chintha, {A. R.} and K. Valtonen and Kuokkala, {V. T.} and S. Kundu and Peet, {M. J.} and Bhadeshia, {H. K.D.H.}", year = "2019", month = "6", day = "15", doi = "10.1016/j.wear.2019.03.028", language = "English", volume = "428-429", pages = "430--437", journal = "Wear", issn = "0043-1648", publisher = "Elsevier", }
@inproceedings{2bf96c849d494065879302b04d949042, title = "Corrosion properties of thermally sprayed bond coatings under plasma sprayed chromia coating in sulfuric acid solutions", abstract = "Plasma sprayed chromia coatings are known to have excellent corrosion and wear properties in highly acidic conditions at ambient and elevated temperatures. In applications requiring extremely good corrosion resistance, the whole components are usually made of a corrosion resistant alloy. For increased adhesion of the ceramic coating to the corrosion resistant substrate material, thermally sprayed metallic bond coatings are used. It is well known that the corrosion environment in such bond coatings between the ceramic top coating and the substrate can be extremely difficult due to the absence of dissolved oxygen, increased concentration of the corrosive electrolytes under the top coating, and galvanic and crevice corrosion mechanisms inside the coating structure. When bond coatings are used, it is of high importance to select the bond layer chemistry and method of production so that the bond coating can survive in such harsh conditions. In the present study, four different bond coatings were studied to evaluate their performance in corrosive acidic electrolytes. The coatings studied were HVOF sprayed Ni-20Cr, Hastelloy C-276 and Ultimet alloy coatings, and plasma sprayed tantalum coating. The substrate material was a solid Hastelloy C-276 metal alloy. The top coating used was plasma sprayed Cr2O3. Corrosion properties of various coating types were studied by electrochemical measurements in sulfuric acid solutions with various concentrations at RT, and by immersion tests at RT and at the temperature of 60°C. The coating microstructures were studied before and after the corrosion tests. The results showed that HVOF sprayed Ni-20Cr and Ultimet alloy coatings were significantly attacked by the sulfuric acid electrolyte, whereas HVOF sprayed Hastelloy C-276 and plasma sprayed Ta coatings performed significantly better.", author = "Petri Vuoristo and Tommi Varis and Damiano Meschini and Giovanni Bolelli and Luca Lusvarghi", year = "2019", month = "5", language = "English", series = "Proceedings of the International Thermal Spray Conference", publisher = "ASM International", pages = "923--930", editor = "F. Azarmi and Y. Lau and J. Veilleux and C. Widener and F. Toma and H. Koivuluoto and K. Balani and H. Li and K. Shinoda", booktitle = "International Thermal Spray Conference and Exposition, ITSC 2019", address = "United States", }
@article{fa9586a897eb4dadb093e44ce7e1ac59, title = "Comparison of various high-stress wear conditions and wear performance of martensitic steels", abstract = "The demanding environments typically encountered by the wear resistant steels create challenges for the materials selection, because the hardness grades of the steels alone do not reveal the true nature of their wear behavior. In this study, five commercial wear resistant steels were tested using three application oriented test methods with five different test variables for abrasion, impact-abrasion, and slurry erosion. All the used test methods produced high-stress conditions that crushed the used mineral abrasive, plastically deformed the sample surfaces, and led to the formation of adiabatic shear bands. When the results produced by the chosen methods were compared, the normalization of the wear losses by the wear area and test time revealed well the differences between the methods. The test methods ranked the steels similarly, but there were clear differences in the wear rates and wear mechanisms between the tests. In addition, the abrasive methods produced surface adiabatic shear bands, while subsurface shear bands were initiated by the more impacting methods. In the studied conditions, the work hardening ability of the steel had a clear influence on its wear resistance, which largely explains the marked differences in the wear rates of the studied commercial 500HB grade steels.", keywords = "Abrasion, Impact wear, Steel, Wear testing, ABRASIVE WEAR, BEHAVIOR, FIELD, RESISTANT STEELS, COMPRESSION, MICROSTRUCTURE", author = "Kati Valtonen and Niko Ojala and Oskari Haiko and Veli-Tapani Kuokkala", year = "2019", month = "4", day = "30", doi = "10.1016/j.wear.2018.12.006", language = "English", volume = "426-427", pages = "3--13", journal = "Wear", issn = "0043-1648", publisher = "Elsevier", number = "Part A", }
@article{19fbee9a35f6432a925491b57f0b174d, title = "Analysis of GaAsBi growth regimes in high resolution with respect to As/Ga ratio using stationary MBE growth", abstract = "The control of Bi incorporation and material properties in III-V-Bi alloys has proved challenging due to their high sensitivity to the epitaxial growth parameters. Here, we present a methodology for determining the variation in the Ga, As, and Bi fluxes and the temperature across a stationary substrate in molecular beam epitaxy. By correlating the flux distributions with material properties, we identify distinct regimes for epitaxy of GaAsBi. In particular, we devise a detailed image of the interplay between Bi incorporation and structural properties of a bulk GaAs 0.96 Bi 0.04 layer grown on GaAs(1 0 0) with respect to the As/Ga ratio. The influence of As/Ga is analyzed with high resolution over the important stoichiometric range (i.e. As/Ga = 0.6–1.6). Growth outside the near-stoichiometric As/Ga regime leads to decreased Bi incorporation, decreased structural quality and the formation of Ga, Ga/Bi or Bi droplets. On the other hand, growth at As/Ga = 1.00–1.17 leads to maximized material quality. For this regime, the surface roughness is further optimized by fine-tuning the As/Ga ratio to suppress surface mounding to a value of 0.5 nm. The results reveal the extreme sensitivity of GaAsBi growth to small variations in the As/Ga ratio, and demonstrate the applicability of stationary growth in studying these effects.", keywords = "A3. Molecular beam epitaxy, B1. Bismuth compounds, B2. Semiconducting III-V materials, B2. Semiconducting ternary compounds", author = "J. Puustinen and J. Hilska and M. Guina", year = "2019", month = "4", day = "1", doi = "10.1016/j.jcrysgro.2019.01.010", language = "English", volume = "511", pages = "33--41", journal = "Journal of Crystal Growth", issn = "0022-0248", publisher = "Elsevier", }
@article{b8e0d9879d8a458ead1ad99258664806, title = "Hydrolysis and drug release from poly(ethylene glycol)-modified lactone polymers with open porosity", abstract = "The ability to release active agents from a porous scaffold structure in situ enables the simultaneous structural support for the cells proliferating and differentiating towards tissue as well as the stimulation of tissue regeneration. Due to the great potentiality of such approach, drug-releasing scaffolds were fabricated from hydrolytically degradable polymers. Three copolymers of poly(ethylene glycol), ɛ-caprolactone, L- and D,L-lactide were synthesized and blended with bone-growth inducing active agents, dexamethasone (DM) and 2-phospho-L-ascorbic acid trisodium salt (AS). Porous scaffolds were prepared by means of super-critical carbon dioxide foaming. In the final scaffold structures, the particle size, location and the water solubility of the drug affected the release kinetics. As the large and water soluble AS particles were more exposed to the buffer solution compared to small DM particles, the AS release was burst-like whereas DM showed a long-term release. The material structure had a significant effect on the release kinetics as the porous scaffolds released active agents faster compared to the solid cylinders. Furthermore, this study showed the strong effect of polymer degradation and wettability on the release, which were more determinative than the pore architecture.", keywords = "2-Phospho-L-ascorbic acid trisodium salt, Bulk degradation, Dexamethasone, Drug release, Hydrolytic degradation, Supercritical carbon dioxide foaming", author = "Sanja Asikainen and Kaarlo Paakinaho and Kyhkynen, {Anna Kaisa} and Markus Hannula and Minna Malin and Niina Ahola and Minna Kellom{\"a}ki and Jukka Sepp{\"a}l{\"a}", year = "2019", month = "4", day = "1", doi = "10.1016/j.eurpolymj.2019.01.056", language = "English", volume = "113", pages = "165--175", journal = "European Polymer Jounal", issn = "0014-3057", publisher = "Elsevier", }
@article{2bdfecc3d5ed4ce19b7d41ccfa9cb614, title = "Mining tailings as raw materials for reaction-sintered aluminosilicate ceramics: Effect of mineralogical composition on microstructure and properties", abstract = "This paper presents studies on the utilization of aluminosilicate-based mining tailings as raw materials for mullite-based ceramics. Based on the 3:2 stoichiometric composition, mullite was synthesised by reactive sintering with a series of powder mixtures with alumina additions. X-ray diffractometry and scanning electron microscopy analyses revealed that, at the specific mineralogical composition, mullite structure formed surrounded by an amorphous glass phase in reaction-sintered powder mixtures. Results demonstrated that the chemical and mineralogical composition of mining tailings do have an effect on mullite formation possibilities and, only with the particular mineralogical composition, the mullite formation is possible regardless of the correct Al:Si ratio in tailings. Physical and mechanical properties of the formed ceramics were defined, showing comparable values to 3:2 mullite reference. Mullite structure formation enables a better thermal resistance up to above 1450 °C of the formed tailings-based ceramics compared to other aluminosilicates, reflecting their utilization potential for refractory ceramic applications.", keywords = "Mining tailings, Mullite, Reaction sintering, Refractory ceramics, Utilization", author = "Marjaana Karhu and Juha Lagerbom and Soili Solismaa and Mari Honkanen and Arnold Ismailov and R{\"a}is{\"a}nen, {Marja Liisa} and Elina Huttunen-Saarivirta and Erkki Lev{\"a}nen and P{\"a}ivi Kivikyt{\"o}-Reponen", note = "EXT={"}Lagerbom, Juha{"}", year = "2019", month = "3", doi = "10.1016/j.ceramint.2018.11.180", language = "English", volume = "45", pages = "4840--4848", journal = "Ceramics International", issn = "0272-8842", publisher = "Elsevier", number = "4", }
@article{aa7fffd852f4466a9c2b35315ee4f920, title = "Solvent Welding and Imprinting Cellulose Nanofiber Films Using Ionic Liquids", abstract = "Cellulose nanofiber films (CNFF) were treated via a welding process using ionic liquids (ILs). Acid-base-conjugated ILs derived from 1,5-diazabicyclo[4.3.0]non-5-ene [DBN] and 1-ethyl-3-methylimidazolium acetate ([emim][OAc]) were utilized. The removal efficiency of ILs from welded CNFF was assessed using liquid-state nuclear magnetic resonance (NMR) spectroscopy and Fourier transform infrared spectroscopy (FTIR). The mechanical and physical properties of CNFF indicated surface plasticization of CNFF, which improved transparency. Upon treatment, the average CNFF toughness increased by 27{\%}, and the films reached a Young's modulus of ∼5.8 GPa. These first attempts for IL {"}welding{"} show promise to tune the surfaces of biobased films, expanding the scope of properties for the production of new biobased materials in a green chemistry context. The results of this work are highly relevant to the fabrication of CNFFs using ionic liquids and related solvents.", author = "Guillermo Reyes and Maryam Borghei and King, {Alistair W. T.} and Johanna Lahti and Rojas, {Orlando J.}", year = "2019", month = "1", day = "14", doi = "10.1021/acs.biomac.8b01554", language = "English", volume = "20", pages = "502--514", journal = "Biomacromolecules", issn = "1525-7797", publisher = "AMER CHEMICAL SOC", number = "1", }
@article{fdf3dbad29be4fd888c96f760e6f7b0f, title = "Characterization of Powder-Precursor HVOF-Sprayed Al2O3-YSZ/ZrO2 Coatings", abstract = "Thermal spraying using liquid feedstock can produce coatings with very fine microstructures either by utilizing submicron particles in the form of a suspension or through in situ synthesis leading, for example, to improved tribological properties. The focus of this work was to obtain a bimodal microstructure by using simultaneous hybrid powder-precursor HVOF spraying, where nanoscale features from liquid feedstock could be combined with the robustness and efficiency of spraying with powder feedstock. The nanostructure was achieved from YSZ and ZrO2 solution-precursors, and a conventional Al2O3 spray powder was responsible for the structural features in the micron scale. The microstructures of the coatings revealed some clusters of unmelted nanosized YSZ/ZrO2 embedded in a lamellar matrix of Al2O3. The phase compositions consisted of γ- and α-Al2O3 and cubic, tetragonal and monoclinic ZrO2. Additionally, some alloying of the constituents was found. The mechanical strength of the coatings was not optimal due to the excessive amount of the nanostructured YSZ/ZrO2 addition. An amount of 10 vol.{\%} or 7 wt.{\%} 8YSZ was estimated to result in a more desired mixing of constituents that would lead to an optimized coating architecture.", keywords = "AlO-ZrO, ceramic matrix composite, coating, HVOF, hybrid, solution-precursor spraying", author = "Jarkko Kiilakoski and Jouni Puranen and Esa Heinonen and Heli Koivuluoto and Petri Vuoristo", year = "2019", month = "1", doi = "10.1007/s11666-018-0816-x", language = "English", volume = "28", pages = "98--107", journal = "Journal of Thermal Spray Technology", issn = "1059-9630", publisher = "ASM International", number = "1-2", }
@article{5cef66389e7b483281649c4de7018c9d, title = "Design, processing, and characterization of an optical core-bioactive clad phosphate fiber for biomedical applications", abstract = "The aim of this study was to fabricate a bioactive optical fiber able to monitor “in situ” its reaction with the body through changes in its optical properties. Core and cladding preforms were prepared with the composition (97.25*(0.50P2O5-0.40SrO-0.10Na2O)-2.5ZnO-0.25Er2O3) and (98.25*(0.50P2O5-0.40SrO-0.10Na2O)-1.75ZnO) (in mol{\%}), respectively, and successfully drawn into a multimode core/clad optical fiber. Optical and near-Infrared images assessed the proper light guiding properties of the fiber. The fibers favor the precipitation of a Ca-P reactive layer at its surface concomitant with a reduction in the fiber diameter, when immersed in SBF, often assigned as a sign of bioactivity. It is clearly shown here that the bio-response of the fiber upon immersion in SBF can be tracked from the decrease in the intensity of the Er3+ ions emission at 1.5 µm. This confirms that the newly developed optical fiber, which combines good optical properties with a suitable bioactive behavior, is a promising platform for the development of novel biomedical devices for biophotonic and photomedical applications. Finally, the successful splicing of the newly developed fiber with commercial optical fibers was an evidence of the possibility to integrate the newly developed phosphate fiber within existing components used in the field of biomedicine.", keywords = "bioactivity, Er luminescence property, optical fiber, phosphate glass", author = "Pablo Lopez-Iscoa and Nirajan Ojha and Diego Pugliese and Ayush Mishra and Regina Gumenyuk and Boetti, {Nadia Giovanna} and Davide Janner and Johann Troles and Bruno Bureau and Catherine Boussard-Pl{\'e}del and Jonathan Massera and Daniel Milanese and Laeticia Petit", year = "2019", doi = "10.1111/jace.16553", language = "English", journal = "JOURNAL OF THE AMERICAN CERAMIC SOCIETY", issn = "0002-7820", publisher = "Wiley", }
@article{7f4b3f57ddeb4d1389795d7605e8f089, title = "Flip-chip Wafer-fused OP-VECSELs emitting 3.65 W at the 1.55-μm waveband", abstract = "Optically-pumped vertical external cavity surface emitting lasers (VECSELs) based on flip-chip gain mirrors emitting at the 1.55-μm wavelength range are reported. The gain mirrors employ wafer-fused InAlGaAs/InP quantum well heterostructures and GaAs/AlAs distributed Bragg reflectors fixed on a diamond heat-sink substrate in a flip-chip geometry, incorporated in a V-cavity configuration. A maximum output power of 3.65 W was achieved for a heat sink temperature of 11°C and employing a 2.2{\%} output coupler. The laser exhibited circular beam profiles for the full emission power range. This demonstration represents more than 5-fold increase of the output power compared to state-of-the-art flip-chip VECSELs previously reported at the 1.55 μm wavelength range. It opens new perspectives for developing practical VECSEL-based laser systems operating at a wavelength range widely used in many applications.", keywords = "diode pumped, Flip-chip devices, Heating systems, Lasers, Mirrors, Optical pumping, Power generation, Semiconductor lasers, Temperature measurement, Vertical cavity surface emitting lasers, Vertical emitting lasers", author = "Alexandru Mereuta and Kostiantyn Nechay and Andrei Caliman and Grigore Suruceanu and Alok Rudra and Pascal Gallo and Mircea Guina and Eli Kapon", year = "2019", doi = "10.1109/JSTQE.2019.2922819", language = "English", volume = "25", journal = "SCIENCE AND ENGINEERING OF COMPOSITE MATERIALS", issn = "0792-1233", number = "6", }
@article{e0fc30aa47e9415aa32225d2dc2319f7, title = "How well can we predict cluster fragmentation inside a mass spectrometer?", abstract = "Fragmentation of molecular clusters inside mass spectrometers is a significant source of uncertainty in a wide range of chemical applications. We have measured the fragmentation of sulfuric acid clusters driving atmospheric new-particle formation, and developed a novel model, based on first principles calculations, capable of quantitatively predicting the extent of fragmentation.", author = "Monica Passananti and Evgeni Zapadinsky and Tommaso Zanca and Juha Kangasluoma and Nanna Myllys and Rissanen, {Matti P.} and Theo Kurt{\'e}n and Mikael Ehn and Michel Attoui and Hanna Vehkam{\"a}ki", year = "2019", doi = "10.1039/c9cc02896j", language = "English", volume = "55", pages = "5946--5949", journal = "Chemical Communications", issn = "1359-7345", publisher = "ROYAL SOC CHEMISTRY", number = "42", }
@article{9fdcb2f6a50e4111bb7283878b69ece6, title = "Low-dimensional formamidinium lead perovskite architectures via controllable solvent intercalation", abstract = "We report the formation of a new class of solvent-intercalated two-dimensional (SI-2D) formamidinium lead halide perovskites. They can be mixed with three-dimensional (3D) stoichiometric perovskites by controlling the ratio of the precursor solutions. The composite leads to greatly improved photoluminescence quantum yield (PLQY) over the 3D compound. The enhanced PLQY is attributed to a type-I band alignment between the 3D and SI-2D, as revealed by first-principles calculations, which results in confined excitons with enhanced radiative recombination. The films exhibited excellent thermal and air stability retaining PLQY > 20{\%} over 2 months in ambient conditions. Assemblies of halide perovskites with mixed dimensionality offer a pathway to enhance optoelectronic performance and device lifetimes.", author = "Mingue Shin and Joonyun Kim and Jung, {Young Kwang} and Tero-Petri Ruoko and Arri Priimagi and Aron Walsh and Byungha Shin", year = "2019", doi = "10.1039/c9tc00379g", language = "English", volume = "7", pages = "3945--3951", journal = "Journal of Materials Chemistry C", issn = "2050-7526", publisher = "Royal Society of Chemistry", number = "13", }
@article{8702626e862a4e33b5ac2d1f4921df7a, title = "Mechanical characterization of pore-graded bioactive glass scaffolds produced by robocasting", abstract = "Since the discovery of 45S5 Bioglass{\circledR} by Larry Hench, bioactive glasses have been widely studied as bone substitute materials and, in more recent years, have also shown great promise for producing three-dimensional scaffolds. The development of additive manufacturing techniques and their application in bone tissue engineering allows the design and fabrication of complex structures with controlled porosity. However, achieving strong and mechanically-reliable bioactive glass scaffolds is still a great challenge. Furthermore, there is a relative paucity of studies reporting an exhaustive assessment of other mechanical properties than compressive strength of glass-derived scaffolds. This research work aimed at determining key mechanical properties of silicate SiO2-Na2O-K2OMgO-CaO-P2O5 glass scaffolds fabricated by robocasting and exhibiting a porosity gradient. When tested in compression, these scaffolds had a strength of 6 MPa, a Young's modulus around 340 MPa, a fracture energy of 93 kJ/m3 and a Weibull modulus of 3, which provides a quantification of the scaffold reliability and reproducibility. Robocasting was a suitable manufacturing method to obtain structures with favorable porosity and mechanical properties comparable to those of the human cancellous bone, which is fundamental regarding osteointegration of bone implants.", keywords = "Bioactive glass, Mechanical properties, Robocasting, Scaffold", author = "Jacopo Barberi and Amy Nommeots-Nomm and Elisa Fiume and Enrica Vern{\'e} and Jonathan Massera and Francesco Baino", note = "EXT={"}Nommeots-Nomm, Amy{"}", year = "2019", doi = "10.1515/bglass-2019-0012", language = "English", volume = "5", pages = "140--147", journal = "Biomedical Glasses", issn = "2299-3932", publisher = "de Gruyter", number = "1", }
@article{826b3abc8bb247cf969071c5e5ddbb63, title = "Process Parameter Impact on Suspension-HVOF-Sprayed Cr2O3 Coatings", abstract = "Chromium oxide (Cr2O3) is commonly used as an atmospheric plasma-sprayed (APS) coating from powder feedstock in applications requiring resistance to sliding wear and corrosion, as well as amenability to texturing, e.g., in anilox rolls. Recently, high-velocity oxy-fuel spray methods involving suspension feedstock have been considered an extremely promising alternative to produce denser and more homogeneous chromium oxide coatings with lower as-sprayed surface roughness, higher hardness and potentially superior wear performance compared to conventional APS-sprayed coatings. In this study, the impact of process parameters namely auxiliary air cleaning nozzles and a transverse air curtain on suspension high-velocity oxy-fuel-sprayed Cr2O3 suspensions is presented. The produced coatings are characterized for their microstructure, mechanical properties and wear resistance by cavitation erosion. The results reveal the importance of optimized air nozzles and air curtain to achieve a vastly improved coating structure and performance.", keywords = "CrO, influence of spray parameters, mechanical properties, SHVOF, suspension spraying", author = "Jarkko Kiilakoski and Richard Trache and Stefan Bj{\"o}rklund and Shrikant Joshi and Petri Vuoristo", year = "2019", doi = "10.1007/s11666-019-00940-7", language = "English", journal = "Journal of Thermal Spray Technology", issn = "1059-9630", publisher = "ASM International", }
@article{0064fd7073394b6b840d5fb20d4dcd36, title = "Structure and Dynamics of Thermosensitive pDNA Polyplexes Studied by Time-Resolved Fluorescence Spectroscopy", abstract = "Combining multiple stimuli-responsive functionalities into the polymer design is an attractive approach to improve nucleic acid delivery. However, more in-depth fundamental understanding how the multiple functionalities in the polymer structures are influencing polyplex formation and stability is essential for the rational development of such delivery systems. Therefore, in this study the structure and dynamics of thermosensitive polyplexes were investigated by tracking the behavior of labeled plasmid DNA (pDNA) and polymer with time-resolved fluorescence spectroscopy using fluorescence resonance energy transfer (FRET). The successful synthesis of a heterofunctional poly(ethylene glycol) (PEG) macroinitiator containing both an atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain-transfer (RAFT) initiator is reported. The use of this novel PEG macroinitiator allows for the controlled polymerization of cationic and thermosensitive linear triblock copolymers and labeling of the chain-end with a fluorescent dye by maleimide-thiol chemistry. The polymers consisted of a thermosensitive poly(N-isopropylacrylamide) (PNIPAM, N), hydrophilic PEG (P), and cationic poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA, D) block, further referred to as NPD. Polymer block D chain-ends were labeled with Cy3, while pDNA was labeled with FITC. The thermosensitive NPD polymers were used to prepare pDNA polyplexes, and the effect of the N/P charge ratio, temperature, and composition of the triblock copolymer on the polyplex properties were investigated, taking nonthermosensitive PD polymers as the control. FRET was observed both at 4 and 37 °C, indicating that the introduction of the thermosensitive PNIPAM block did not compromise the polyplex structure even above the polymer's cloud point. Furthermore, FRET results showed that the NPD- and PD-based polyplexes have a less dense core compared to polyplexes based on cationic homopolymers (such as PEI) as reported before. The polyplexes showed to have a dynamic character meaning that the polymer chains can exchange between the polyplex core and shell. Mobility of the polymers allow their uniform redistribution within the polyplex and this feature has been reported to be favorable in the context of pDNA release and subsequent improved transfection efficiency, compared to nondynamic formulations.", author = "Fliervoet, {Lies A.L.} and Lisitsyna, {Ekaterina S.} and Durandin, {Nikita A.} and Ilias Kotsis and Maas-Bakker, {Roel F.M.} and Marjo Yliperttula and Hennink, {Wim E.} and Elina Vuorimaa-Laukkanen and Tina Vermonden", year = "2019", doi = "10.1021/acs.biomac.9b00896", language = "English", journal = "Biomacromolecules", issn = "1525-7797", publisher = "AMER CHEMICAL SOC", }
@article{fef8af0c975949e18cc125b3f21a22c4, title = "Temperature scanning stress relaxation behavior of water responsive and mechanically adaptive elastomer nanocomposites", abstract = "The decrease of stress at constant strain, that is, the stress relaxation process as a function of temperature, is a central mechanical characteristics of elastomer nanocomposites for their potential applications. However, in the conventional stress relaxation test, the relaxation behavior is usually determined as a function of time at constant temperature. The present work reports the temperature scanning stress relaxation (TSSR) characteristics of a new kind of mechanically adaptive elastomer nanocomposite by monitoring the nonisothermal relaxation behavior as a function of temperature. This kind of adaptive elastomer nanocomposite was prepared by introducing calcium sulfate (CaSO4), as the water-responsive phase into the hydrophilic elastomer matrix. The influence of water-induced structural changes on TSSR behavior was investigated. Water treatment had a strong effect on the shape of the relaxation spectrum of the nanocomposite. It was revealed that the in situ development of hydrated nano-rod crystal structures of CaSO4 in the elastomer matrix was responsible for the changes in the mechanical relaxation behavior of the composites. Atomic force microscopy was used to verify this nano-rod crystal morphology in the elastomer matrix. The mechanism of water-induced mechanical reinforcement of the composite was explored from dynamic mechanical analysis of the material and correlated with its stress relaxation behavior.", keywords = "adaptive elastomer nanocomposite, calcium sulphate, mechanical reinforcement, morphology, temperature scanning stress relaxation", author = "Banerjee, {Shib Shankar} and Natarajan, {Tamil S.} and {Subramani B.}, Eshwaran and Sven Wie{\ss}ner and Andreas Janke and Gert Heinrich and Amit Das", year = "2019", doi = "10.1002/app.48344", language = "English", journal = "Journal of Applied Polymer Science", issn = "0021-8995", publisher = "Wiley", }
@article{9424213af2bb4d33a65461a4be3289c3, title = "Reversible photodoping of TiO2 nanoparticles", abstract = "Observations on strong photochromic effect of crystalline TiO2 quantum dots (mean size ≈ 4 nm) are presented. The synthesized quantum dots consist of irregularly shaped anatase TiO2 nanoparticles (NPs) and are dispersed in butanol (8 {\%} by mass). Obtained NPs exhibit a dramatic photo-response to UV light, enabling effective transmittance modula-tion of in a broad wavelength range extending from visible to near-infrared region, and even the thermal black body radiation regime beyond 10 μm. The exceptional photo-response is attributed to hole-scavenging by butanol, TiO2 self-reduction, injection of electrons to the conduction band, and consequent localized surface plasmon resonances in NPs. Observed optical effect is reversible and the initial high transmittance state can be restored simply by exposing the NPs to air. Applied NP synthesis route is economic and can be easily scaled for applications such as smart window technol-ogies.", keywords = "tio2, nano, nanoparticle, photochromic, anatase, light, photonics, functional", author = "Urmas Joost and Andris Sutka and Marek Oja and Krisjanis Smits and Nicola Doebelin and Ardi Loot and Martin J{\"a}rvek{\"u}lg and Mika Hirsim{\"a}ki and Mika Valden and Ergo Nommiste", note = "INT=fot,{"}Joost, Urmas{"}", year = "2018", month = "12", day = "26", doi = "10.1021/acs.chemmater.8b04813", language = "English", volume = "30", pages = "8968--8974", journal = "Chemistry of Materials", issn = "0897-4756", publisher = "American Chemical Society", number = "24", }
@article{ae6b07f390364ddc84320a8fa1cb0729, title = "Optical properties of GaAs1-xBix/GaAs quantum well structures grown by molecular beam epitaxy on (100) and (311)B GaAs substrates", abstract = "In this work, the electronic bandstructure of GaAs1-xBix/GaAs single quantum well (QW) samples grown by molecular beam epitaxy is investigated by photomodulated reflectance (PR) measurements as a function of Bi content (0.0065 ≤ x ≤ 0.0215) and substrate orientation. The Bi composition is determined via simulation of high-resolution x-ray diffraction measurement and is found to be maximized in the 2.15{\%}Bi and 2.1{\%}Bi samples grown on (100) and (311)B GaAs substrates. However, the simulations indicate that the Bi composition is not only limited in the GaAsBi QW layer but extends out of the GaAsBi QW towards the GaAs barrier and forms a GaAsBi epilayer. PR spectra are fitted with the third derivative function form (TDFF) to identify the optical transition energies. We analyze the TDFF results by considering strain-induced modification on the conduction band (CB) and splitting of the valence band (VB) due to its interaction with the localized Bi level and VB interaction. The PR measurements confirm the existence of a GaAsBi epilayer via observed optical transitions that belong to GaAsBi layers with various Bi compositions. It is found that both Bi composition and substrate orientation have strong effects on the PR signal. Comparison between TDFF and calculated optical transition energies provides a bandgap reduction of 92 meV/{\%}Bi and 36 meV/{\%}Bi and an interaction strength of the isolated Bi atoms with host GaAs valence band (C BiM ) of 1.7 eV and 0.9 eV for (100) and (311)B GaAs substrates, respectively.", keywords = "high-index substrate, oriented GaAsBi, photomodulated reflectance, strained quantum well, type I band line-up", author = "M. Gunes and Ukelge, {M. O.} and O. Donmez and A. Erol and C. Gumus and H. Alghamdi and Galeti, {H. V.A.} and M. Henini and M. Schmidbauer and J. Hilska and J. Puustinen and M. Guina", year = "2018", month = "11", day = "13", doi = "10.1088/1361-6641/aaea2e", language = "English", volume = "33", journal = "Semiconductor Science and Technology", issn = "0268-1242", publisher = "IOP Publishing", number = "12", }
@article{80fd31749ed54a11926772a70920ba0e, title = "Solvothermal synthesis derived Co-Ga codoped ZnO diluted magnetic degenerated semiconductor nanocrystals", abstract = "Here we are reporting solvothermal synthesis derived diluted magnetic and plasmonic Co-Ga co-doped ZnO nanocrystals with high magnetization values (from 1.02 to 4.88 emu/g) at room temperature. Co-Ga co-doped ZnO nanocrystals show up to 2 fold increase in saturation magnetization compared to Co doped ZnO nanocrystals at the same Co concentration, with the observed room temperature magnetization higher than previously reported values for multifunctional magnetic and plasmonic nanocrystals, and the effect of Ga suggesting some role of the correspondingly introduced itinerant charge. While at the lowest Ga content the nanoparticles appear homogeneously doped, we note that already a moderate Ga content of several percent triggers a fraction of Co to segregate in metallic form in the bulk of the nanoparticles. However, the amount of segregated Co is not sufficient to account for the total effect, whereas a dominating contribution to the observed magnetism has to be related to itinerant charge mediated exchange interactions.", keywords = "Degenerated semiconductors, Diluted magnetic semiconductors, Doping, Plasmonic nanocrystals, Solvothermal synthesis, ZnO", author = "Andris Šutka and Tanel K{\"a}{\"a}mbre and Urmas Joost and Kuno Kooser and Mati Kook and Duarte, {Roberto Felix} and Vambola Kisand and Mikhael Maiorov and Nicola D{\"o}belin and Krisjanis Smits", note = "int=fot,{"}Joost, Urmas{"}", year = "2018", month = "9", day = "30", doi = "10.1016/j.jallcom.2018.05.036", language = "English", volume = "763", pages = "164--172", journal = "Journal of Alloys and Compounds", issn = "0925-8388", publisher = "Elsevier", }
@article{e0170ee533154d3c8474698ebdd8f127, title = "Mechanical, thermal, and burning properties of viscose fabric composites: Influence of epoxy resin modification", abstract = "The influence of epoxy resin modification by 3-aminopropyltriethoxysilane (APTES) on various properties of warp knitted viscose fabric is reported in this study. Dynamic mechanical, impact resistance, flexural, thermal properties, and burning behavior of the epoxy/viscose fabric composites are studied with respect to varying content of silane coupling agent. The results obtained for APTES-modified epoxy resin based composites reinforced with unmodified viscose fabric composites are compared to unmodified epoxy resin based composites reinforced with APTES-modified viscose fabric. The dynamic mechanical behavior of the APTES-modified resin based composites indicates improved interfacial adhesion. The composites prepared from modified epoxy resin exhibited a twofold increase in impact resistance. The improved adhesion between the fiber and modified resin was also visible from the scanning electron microscope analysis of the impact fracture surface. There was less influence of resin modification on the flexural properties of the composites. The 5{\%} APTES modification induced early degradation of composites compared to all other composites. The burning rate of all the composites under study is rated to be satisfactory for use in automotive interior applications.", keywords = "cellulose and other wood products, functionalization of polymers, mechanical properties, thermal properties, thermosets", author = "Rathish Rajan and Egidija Rainosalo and Ramamoorthy, {Sunil Kumar} and Thomas, {Selvin P.} and Janez Zavašnik and Jyrki Vuorinen and Mikael Skrifvars", note = "EXT={"}Skrifvars, Mikael{"}", year = "2018", month = "9", day = "20", doi = "10.1002/app.46673", language = "English", volume = "135", journal = "Journal of Applied Polymer Science", issn = "0021-8995", publisher = "Wiley", number = "36", }
@article{84d167933d7c406cbf00798356fd68ae, title = "Post operation inactivation of acidophilic bioleaching microorganisms using natural chloride-rich mine water", abstract = "The H2020 BIOMOre project (www.biomore.info, Grant Agreement #642456) tests the feasibility of in situ bioleaching of copper in deep subsurface deposits in the Rudna mine, Poland. Copper is leached using biologically produced ferric iron solution, which is recycled back to the in situ reactor after re-oxidation by iron-oxidizing microorganisms. From a post operational point of view, it is important that the biological processes applied during the operation can be controlled and terminated. Our goal was to determine the possibility to use natural saline mine water for the inactivation of the introduced iron-oxidizing microorganisms remaining in the in situ reactor after completion of the leaching process of the ore block. Aerobic and anaerobic microcosms containing acid-leached (pH 2) sandstone or black shale from the Kupferschiefer in the Rudna mine were further leached with the effluent from a ferric iron generating bioreactor at 30 °C for 10 days to simulate the in situ leaching process. After the removal of the iron solution, residing iron-oxidizing microorganisms were inactivated by filling the microcosms with chloride-rich water (65 g L−1 Cl‐) originating from the mine. The chloride-rich water irreversibly inactivated the iron-oxidizing microorganisms and showed that the naturally occurring saline water of the mine can be used for long-term post process inactivation of bioleaching microorganisms", keywords = "BIOMOre, in situ bioleaching, Inactivation, Iron-oxidizing bacteria, Quantitative PCR", author = "Malin Bomberg and Hanna Miettinen and Margareta Wahlstr{\"o}m and Tommi Kaartinen and Sarita Ahoranta and Aino-Maija Lakaniemi and P{\"a}ivi Kinnunen", year = "2018", month = "9", day = "1", doi = "10.1016/j.hydromet.2018.06.013", language = "English", volume = "180", pages = "236--245", journal = "Hydrometallurgy", issn = "0304-386X", publisher = "Elsevier", }
@article{6ebca1277b00429da60c8c4949ce766f, title = "Recent progress in biohydrometallurgy and microbial characterisation", abstract = "Since the discovery of microbiological metal dissolution, numerous biohydrometallurgical approaches have been developed to use microbially assisted aqueous extractive metallurgy for the recovery of metals from ores, concentrates, and recycled or residual materials. Biohydrometallurgy has helped to alleviate the challenges related to continually declining ore grades by transforming uneconomic ore resources to reserves. Engineering techniques used for biohydrometallurgy span from above ground reactor, vat, pond, heap and dump leaching to underground in situ leaching. Traditionally biohydrometallurgy has been applied to the bioleaching of base metals and uranium from sulfides and the biooxidation of sulfidic refractory gold ores and concentrates before cyanidation. More recently the interest in using bioleaching for oxide ore and waste processing, as well as extracting other commodities such as rare earth elements has been growing. Bioprospecting, adaptation, engineering and storing of microorganisms has increased the availability of suitable biocatalysts for biohydrometallurgical applications. Moreover, the advancement of microbial characterisation methods has increased the understanding of microbial communities and their capabilities in the processes. This paper reviews recent progress in biohydrometallurgy and microbial characterisation.", keywords = "Biohydrometallurgy, Bioleaching, Biooxidation, Characterisation, Microbiology", author = "Kaksonen, {Anna H.} and Boxall, {Naomi J.} and Yosephine Gumulya and Khaleque, {Himel N.} and Christina Morris and Tsing Bohu and Cheng, {Ka Yu} and Usher, {Kayley M.} and Aino-Maija Lakaniemi", note = "EXT={"}Kaksonen, Anna H.{"}", year = "2018", month = "9", day = "1", doi = "10.1016/j.hydromet.2018.06.018", language = "English", volume = "180", pages = "7--25", journal = "Hydrometallurgy", issn = "0304-386X", publisher = "Elsevier", }
@article{525350c93f114520a1dba2d352d170e1, title = "Near-threshold high spin amplification in a 1300 nm GaInNAs spin laser", abstract = "Using continuous-wave optical pumping of a spin-VCSEL at room temperature, we find high spin amplification of the pump close to threshold within the communications wavelength window, here at 1300 nm. This facilitates a strong switch from left to right circularly polarised light emission, which has potential applications in polarisation encoding for data communications. We use a simple spin flip model to fit the experimental results and discuss the VCSEL parameters that affect this amplification.", keywords = "spin amplification, spin laser, spin VCSEL", author = "Ben Cemlyn and Mike Adams and Edmund Harbord and Nianqiang Li and Henning, {Ian D.} and Ruth Oulton and Korpij{\"a}rvi, {Ville Markus} and Mircea Guina", year = "2018", month = "8", day = "1", doi = "10.1088/1361-6641/aad42e", language = "English", volume = "33", journal = "Semiconductor Science and Technology", issn = "0268-1242", publisher = "IOP Publishing", number = "9", }
@article{4b385475d33e40afa397e7bd70456ce2, title = "Exciton localization and structural disorder of GaAs1-xBix/GaAs quantum wells grown by molecular beam epitaxy on (311)B GaAs substrates", abstract = "In this work, we have investigated the structural and optical properties of GaAs(1-x)Bix/GaAs single quantum wells (QWs) grown by molecular beam epitaxy on GaAs (311)B substrates using x-ray diffraction, atomic force microscopy, Fourier-transform Raman (FT-Raman) and photoluminescence spectroscopy techniques. The FT-Raman results revealed a decrease of the relative intensity ratio of transverse and longitudinal optical modes with the increase of Bi concentration, which indicates a reduction of the structural disorder with increasing Bi incorporation. In addition, the PL results show an enhancement of the optical efficiency of the structures as the Bi concentration is increased due to important effects of exciton localization related to Bi defects, nonradiative centers and alloy disorder. These results provide evidence that Bi is incorporated effectively into the QW region. Finally, the temperature dependence of the PL spectra has evidenced two distinct types of defects related to the Bi incorporation, namely Bi clusters and pairs, and alloy disorder and potential fluctuation.", keywords = "dilute bismide, exciton localization, photoluminescence, structural disorder", author = "Prando, {G. A.} and {Orsi Gordo}, V. and J. Puustinen and J. Hilska and Alghamdi, {H. M.} and G. Som and M. Gunes and M. Akyol and S. Souto and Rodrigues, {A. D.} and Galeti, {H. V.A.} and M. Henini and Gobato, {Y. Galv{\~a}o} and M. Guina", year = "2018", month = "7", day = "17", doi = "10.1088/1361-6641/aad02e", language = "English", volume = "33", journal = "Semiconductor Science and Technology", issn = "0268-1242", publisher = "IOP Publishing", number = "8", }
@article{80230b6e198b4a03b2f18c2de3dd22da, title = "Luminescence of Er3+ doped oxyfluoride phosphate glasses and glass-ceramics", abstract = "Glasses with the composition (75 NaPO3-(25-x) CaO-xCaF2) (in mol {\%}) were prepared with 0.15 mol{\%} of Er2O3. The effect of the glass composition and of heat treatment on the spectroscopic properties of the newly developed glasses is reported. With the progressive replacement of CaO by CaF2, the Er3+:4I13/2 lifetime and the intensity of the upconversion emission increase whereas the intensity of the emission at 1.5 μm decreases due to the decrease in the phonon energy in the as-prepared glasses. The glasses were heat treated at 20 °C above their respective glass transition temperature for 17 h to form nuclei and then at their crystallization temperature from 15min to 1 h to grow the nuclei into crystals. The heat treatment leads to the precipitation of crystalline phases, the composition of which depends upon the glass composition. As the Er3+:4I13/2 lifetime increases and the intensity of the upconversion increases for the glass with x = 0 after heat treatment, the Er3+ ions are expected to be incorporated into the phosphate-based crystals. However, as the shape of the emission band at 1.5 μm remains unchanged and the intensity of the upconversion decreases significantly after heat treatment of the glasses with x > 10, the crystals found in the glass-ceramics with x > 10 are thought to free of Er3+ ions. Although Er3+ ions entered in the CaF2 crystals precipitating in aluminosilicate glass, the Er3+ ions are believed to remain in the amorphous phosphate part of the glass-ceramic containing CaF2 crystals.", keywords = "CaF crystals in glass, Er luminescence, Oxyfluoride phosphate glasses and glass-ceramics", author = "A. Nommeots-Nomm and Boetti, {N. G.} and T. Salminen and J. Massera and M. Hokka and L. Petit", year = "2018", month = "6", day = "30", doi = "10.1016/j.jallcom.2018.04.101", language = "English", volume = "751", pages = "224--230", journal = "Journal of Alloys and Compounds", issn = "0925-8388", publisher = "Elsevier", }
@article{82472270ed6743e08064dbb0bb5d493c, title = "The effect of carbon and nickel additions on the precursor synthesis of Cr3C2-Ni nanopowder", abstract = "Decreasing crystal size to nanoscale is a proven method to enhance material properties. In this study, nanosize Cr3C2 and Cr3C2-Ni were synthetized and the reaction sequence was studied. Aqueous precursors using only water-soluble raw materials with varying carbon contents and a nickel addition were spray-dried. Glycine was used as a carbon source and chromium acetate hydroxide as a chromium source in the precursor solutions. Nickel nitrate hexahydrate was introduced as a nickel source to yield a metallic binder into the carbide nanopowder.Resulting powders were heat-treating to identify an applicable precursor composition producing the targeted Cr3C2 phase with crystal size of tens of nanometers. Thermal synthesis tests of the precursor powders to yield Cr3C2 took place at a temperature between 900 and 1300 °C under an Argon atmosphere. The synthesis of nanosize Cr3C2-Ni powder was successful at 1000 °C in 30 min, in a case of the best precursor. In order to produce the carbide phase with no residual oxide traces, relative carbon load has to be 48 wt{\%}, while the stoichiometric amount of carbon in Cr3C2 is 13 wt{\%}. When also introducing the nickel source into the precursor, an even higher carbon load was required. The carbon surplus needed to enable the Cr3C2 synthesis attributes to the non-homogeneity of the precursor composition.The chemical synthesis starting from water-soluble raw materials is a promising way of preparing nanosize Cr3C2-Ni with the targeted phase configuration.", keywords = "A. Nanosize CrC synthesis, A. Powders: chemical preparation, B. Grain size, D. Carbides, E. Wear parts", author = "Kimmo Kaunisto and Minna Kotilainen and Marjaana Karhu and Juha Lagerbom and Tommi Vuorinen and Mari Honkanen and Minnamari Vippola and Erja Turunen", note = "EXT={"}Vuorinen, Tommi{"} EXT={"}Lagerbom, Juha{"} EXT={"}Kaunisto, Kimmo{"}", year = "2018", month = "6", day = "1", doi = "10.1016/j.ceramint.2018.02.146", language = "English", volume = "44", pages = "9338--9346", journal = "Ceramics International", issn = "0272-8842", publisher = "Elsevier", number = "8", }
@article{bf71748a955d488bac69129ab5f9bc75, title = "Influence of the phosphate glass melt on the corrosion of functional particles occurring during the preparation of glass-ceramics", abstract = "We report our findings on the impact of the glass composition on the corrosion of microparticles occurring during the preparation of glass-ceramics using the direct doping method. Microparticles (MPs) with the composition Sr4Al14O25:Eu2+,Dy3+ with blue-green persistent luminescence were chosen as the changes in their spectroscopic properties can be related to the MPs’ corrosion. The MPs were added in phosphate-based glasses with different compositions. When using the same doping parameters, the glass system with the composition 90NaPO3-10Na2O (mol{\%}) was found to be the least corrosive on the MPs whereas the glass system with the composition 90NaPO3-10NaF (mol{\%}) is the most corrosive on the MPs probably due to their different viscosity at 575 °C, the temperature at which the MPs are added in the glass melts.", keywords = "Corrosion, Direct doping method, Glass melt, Phosphate glass-ceramics, SrAlO:Eu, Dy microparticles", author = "N. Ojha and T. Laihinen and T. Salminen and M. Lastusaari and L. Petit", year = "2018", month = "6", doi = "10.1016/j.ceramint.2018.03.267", language = "English", volume = "44", pages = "11807--11811", journal = "Ceramics International", issn = "0272-8842", publisher = "Elsevier", number = "10", }
@article{1d6e523fd6304d9db9e52e133c70af55, title = "The effects of laser patterning 10CeTZP-Al2O3 nanocomposite disc surfaces: Osseous differentiation and cellular arrangement in vitro", abstract = "Customized square grid arrangements of different groove depths (1.0, 1.5 and 3.0 μm) and separations (10 and 30 μm) were successfully laser patterned, using a nanosecond pulsed fibre laser, on the surface of 10 mol{\%} ceria-stabilized zirconia and alumina (10CeTZP-Al2O3) nanocomposite discs (diameter: 10 mm; thickness: 1.5 mm). The patterned surfaces and the in vitro biological response of osteoblasts (SAOS-2) towards them were thoroughly analysed. In terms of composition, the laser treatment was found to cause superficial monoclinic-tetragonal zirconia phase transformation and alumina evaporation. In vitro, the most effective grid configuration for osseous differentiation was found to be 1.5 μm groove depth and 10 μm groove separation, and confocal microscopy revealed that the cells show a tendency to be sorted as groove depth increases. It is thought that custom-made patterns could be produced to guide cell attachment in vivo, which could favour implant integration and reduce healing time.", keywords = "Alumina, Cellular arrangement, Ceramic nanocomposite, Laser patterning, Osseous differentiation, Zirconia", author = "Lidia Goyos-Ball and Catuxa Prado and Raquel D{\'i}az and Elisa Fern{\'a}ndez and Arnold Ismailov and Tero Kumpulainen and Erkki Lev{\"a}nen and Ram{\'o}n Torrecillas and Adolfo Fern{\'a}ndez", year = "2018", month = "6", doi = "10.1016/j.ceramint.2018.02.164", language = "English", volume = "44", pages = "9472--9478", journal = "Ceramics International", issn = "0272-8842", publisher = "Elsevier", number = "8", }
@article{e1d6c387c66e4076a93fc86551bd35c9, title = "A study of electric transport in n- and p-type modulation-doped GaInNAs/GaAs quantum well structures under a high electric field", abstract = "We present the results of longitudinal carrier transport under a high electrical field in n- and p-type modulation-doped Ga0.68In0.32NyAs1-y/GaAs (y = 0.009, 0.017) quantum well (QW) structures. Nitrogen composition-dependent drift velocities of electrons are observed to be saturated at and at 77 K for the samples with y = 0.009 and y = 0.017, respectively, while the drift velocities of holes do not saturate but slightly increase at the applied electric field in the range of interest. The hole drift velocity is observed to be higher than the electron drift velocity. The electron mobility exhibits an almost temperature-independent characteristic. On the other hand, the hole mobility exhibits a conventional temperature dependence of modulation-doped QW structures. As the temperature increases, the drift velocity of the electrons exhibits an almost an temperature-insensitive characteristic, but, on the other hand, for holes, drift velocity decreases approximately from 107-106 cm s-1. It is observed that the drift velocities of electrons and holes are N-dependent and suppressed at higher electric fields. Furthermore, experimental results show that there is no evidence of negative differential velocity (NDV) behaviour for both n- and p-type samples. To explore the observed electron and hole drift velocity characteristic at high electric fields, we use a simple theoretical model for carrier transport, which takes into account the effect of non-drifting hot phonons. The mobility mapping technique (comparison method) is used to extract hot hole temperature in order to employ it in the non-drifted phonon distribution and to obtain the drift velocity-electric field curves. Then hot electron temperatures are obtained from the drift velocity-electric field curves as a fit parameter using non-drifted hot phonon dynamics. The analytical model is well-matched to the experimental -E curves, indicating that carrier-hot phonon scattering is the main reason for suppressing the NDV mechanism in GaInNAs/GaAs QW structures with a carrier density higher than 1017 cm-3.", keywords = "dilute nitride, GaInNAs, hot phonons, hot-electron and hole temperature, modulation-doped GaInNAs/GaAs quantum well", author = "F. Sarcan and S. Mutlu and E. Cokduygulular and O. Donmez and A. Erol and J. Puustinen and M. Guina", year = "2018", month = "5", day = "4", doi = "10.1088/1361-6641/aabc39", language = "English", volume = "33", journal = "Semiconductor Science and Technology", issn = "0268-1242", publisher = "IOP Publishing", number = "6", }
@article{db660d2d3d394d0bba940cee5f37cc35, title = "Accurate Binding of Sodium and Calcium to a POPC Bilayer by Effective Inclusion of Electronic Polarization", abstract = "Binding affinities and stoichiometries of Na+ and Ca2+ ions to phospholipid bilayers are of paramount significance in the properties and functionality of cellular membranes. Current estimates of binding affinities and stoichiometries of cations are, however, inconsistent due to limitations in the available experimental and computational methods. In this work, we improve the description of the binding details of Na+ and Ca2+ ions to a 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC) bilayer by implicitly including electronic polarization as a mean field correction, known as the electronic continuum correction (ECC). This is applied by scaling the partial charges of a selected state-of-the-art POPC lipid model for molecular dynamics simulations. Our improved ECC-POPC model reproduces not only the experimentally measured structural parameters for the ion-free membrane, but also the response of lipid headgroup to a strongly bound cationic amphiphile, as well as the binding affinities of Na+ and Ca2+ ions. With our new model, we observe on the one side negligible binding of Na+ ions to POPC bilayer, while on the other side stronger interactions of Ca2+ primarily with phosphate oxygens, which is in agreement with the previous interpretations of the experimental spectroscopic data. The present model results in Ca2+ ions forming complexes with one to three POPC molecules with almost equal probabilities, suggesting more complex binding stoichiometries than those from simple models used to interpret the NMR data previously. The results of this work pave the way to quantitative molecular simulations with realistic electrostatic interactions of complex biochemical systems at cellular membranes.", author = "Josef Melcr and Hector Martinez-Seara and Ricky Nencini and Jiř{\'i} Kolafa and Pavel Jungwirth and Ollila, {O. H. Samuli}", note = "EXT=”Martinez-Seara, Hector” EXT={"}Ollila, O. H. Samuli{"}", year = "2018", month = "4", day = "26", doi = "10.1021/acs.jpcb.7b12510", language = "English", volume = "122", pages = "4546--4557", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "16", }
@article{6f244ae77a364f37b4ff1e1a4c8396af, title = "Powering of an HTS dipole insert-magnet operated standalone in helium gas between 5 and 85 K", abstract = "This paper describes the standalone magnet cold testing of the high temperature superconducting (HTS) magnet Feather-M2.1-2. This magnet was constructed within the European funded FP7-EUCARD2 collaboration to test a Roebel type HTS cable, and is one of the first high temperature superconducting dipole magnets in the world. The magnet was operated in forced flow helium gas with temperatures ranging between 5 and 85 K. During the tests a magnetic dipole field of 3.1 T was reached inside the aperture at a current of 6.5 kA and a temperature of 5.7 K. These values are in agreement with the self-field critical current of the used SuperOx cable assembled with Sunam tapes (low-performance batch), thereby confirming that no degradation occurred during winding, impregnation, assembly and cool-down of the magnet. The magnet was quenched many tens of times by ramping over the critical current and no degradation nor training was evident. During the tests the voltage over the coil was monitored in the microvolt range. An inductive cancellation wire was used to remove the inductive component, thereby significantly reducing noise levels. Close to the quench current, drift was detected both in temperature and voltage over the coil. This drifting happens in a time scale of minutes and is a clear indication that the magnet has reached its limit. All quenches happened approximately at the same average electric field and thus none of the quenches occurred unexpectedly.", keywords = "cold testing, high temperature superconductors, superconducting accelerator magnets, superconducting magnets", author = "Nugteren, {J. Van} and G. Kirby and H. Bajas and M. Bajko and A. Ballarino and L. Bottura and A. Chiuchiolo and Contat, {P. A.} and M. Dhall{\'e} and M. Durante and P. Fazilleau and A. Fontalva and P. Gao and W. Goldacker and Kate, {H. Ten} and A. Kario and V. Lahtinen and C. Lorin and A. Markelov and J. Mazet and A. Molodyk and J. Murtom{\"a}ki and N. Long and J. Perez and C. Petrone and F. Pincot and Rijk, {G. De} and L. Rossi and S. Russenschuck and J. Ruuskanen and K. Schmitz and A. Stenvall and A. Usoskin and G. Willering and Y. Yang", note = "EXT={"}Murtom{\"a}ki, J.{"}", year = "2018", month = "4", day = "25", doi = "10.1088/1361-6668/aab887", language = "English", volume = "31", journal = "Superconductor Science and Technology", issn = "0953-2048", publisher = "IOP Publishing", number = "6", }
@article{c6e06cd42cbc40c0a13c82e95dcb6d12, title = "Membrane bound COMT isoform is an interfacial enzyme: General mechanism and new drug design paradigm", abstract = "The enzyme catechol-O-methyltransferase (COMT) has water soluble (S-COMT) and membrane associated (MB-COMT), bitopic, isoforms. Of these MB-COMT is a drug target in relation to the treatment of Parkinson's disease. Using a combination of computational and experimental protocols, we have determined the substrate selection mechanism specific to MB-COMT. We show: (1) substrates with preferred affinity for MB-COMT over S-COMT orient in the membrane in a fashion conducive to catalysis from the membrane surface and (2) binding of COMT to its cofactor ADOMET induces conformational change that drives the catalytic surface of the protein to the membrane surface, where the substrates and Mg2+ ions, required for catalysis, are found. Bioinformatics analysis reveals evidence of this mechanism in other proteins, including several existing drug targets. The development of new COMT inhibitors with preferential affinity for MB-COMT over S-COMT is now possible and insight of broader relevance, into the function of bitopic enzymes, is provided.", author = "Aniket Magarkar and Petteri Parkkila and Tapani Viitala and Tatu Lajunen and Edouard Mobarak and Giuseppe Licari and Oana Cramariuc and Eric Vauthey and Tomasz R{\'o}g and Alex Bunker", year = "2018", month = "4", day = "11", doi = "10.1039/c8cc00221e", language = "English", volume = "54", pages = "3440--3443", journal = "Chemical Communications", issn = "1359-7345", publisher = "ROYAL SOC CHEMISTRY", number = "28", }
@article{76ad6b2ca8db48b49520940f5c229fab, title = "Effect of nozzle geometry on the microstructure and properties of hvaf-sprayed wc-10co4cr and cr3c2-25nicr coatings", abstract = "Thermally sprayed hard metal coatings are the industrial standard solution for numerous demanding applications to improve wear resistance. In the aim of improving coating quality by utilising finer particle size distributions, several approaches have been studied to control the spray temperature. The most viable solution is to use the modern high velocity air-fuel (HVAF) spray process, which has already proven to produce high-quality coatings with dense structures. In HVAF spray process, the particle heating and acceleration can be efficiently controlled by changing the nozzle geometry. In this study, fine WC-10Co4Cr and Cr3C2-25NiCr powders were sprayed with three nozzle geometries to investigate their effect on the particle temperature, velocity and coating microstructure. The study demonstrates that the particle melting and resulting carbide dissolution can be efficiently controlled by changing the nozzle geometry from cylindrical to convergent–divergent. Moreover, the average particle velocity was increased from 780 to over 900 m/s. The increase in particle velocity significantly improved the coating structure and density. Further evaluation was carried out to resolve the effect of particle in-flight parameters on coating structure and cavitation erosion resistance, which was significantly improved in the case of WC-10Co4Cr coatings with the increasing average particle velocity.", keywords = "cavitation erosion < properties, chromium carbide < feedstock, diagnostics < processing, HP/HVOF < processing, HVAF < processing, HVOF < processing, WC-CO-Cr < feedstock", author = "V. Matikainen and H. Koivuluoto and P. Vuoristo and J. Schubert and Houdkov{\'a}", year = "2018", month = "4", day = "1", doi = "10.1007/s11666-018-0717-z", language = "English", volume = "27", pages = "680--694", journal = "Journal of Thermal Spray Technology", issn = "1059-9630", publisher = "ASM International", number = "4", }
@article{bfca8f2791b348208cd4441873395a26, title = "Properties of HVOF-sprayed Stellite-6 coatings", abstract = "Stellite-6 coatings were deposited onto AISI 304 stainless steel substrate by gas-fueled HVOF spraying, systematically varying the process parameter settings. By operating the HVOF torch with a fuel-rich mixture, dense coatings (<1{\%} porosity) are produced, containing up to ≈3 vol{\%} oxide inclusions. A substantial amount of a Cr-rich f.c.c. phase is found, mainly produced by quenching of molten lamellae, and distinct from the equilibrium, Co-based f.c.c. solid solution retained in unmelted particles. These coatings exhibit pseudo-passive behavior and survive 5 cycles (100 h) of the Corrodkote test (ASTM B380-97) with no substrate corrosion. Coatings obtained from oxygen-rich mixtures, on the other hand, contain fewer oxide inclusions but also greater porosity, and do not protect the substrate against corrosion. The wear behavior of the coatings is less influenced by deposition conditions. In ball-on-disk dry sliding tests, all coatings exhibit wear rates of 2–3 × 10−5 mm3/(N·m), higher than those reported for bulk or clad Stellite, because of interlamellar delamination. Strain-induced, “martensitic” phase transformation from the f.c.c. structure to a h.c.p. one is observed over a 1–2 μm depth below the contact surface. Additional tribo-oxidation is onset when frictional heat dissipation has heated the wear debris enough to trigger its reaction with the environment. Correspondingly, a transition to a regime of higher friction occurs (from ≈0.6 to ≈0.8). At 400 °C, lamellar delamination is suppressed but wear rates rise to 5–8 × 10−5 mm3/(N·m) because of abrasive and adhesive wear. At 800 °C, a dense “glaze” tribofilm is formed by sintered debris particles, firmly bonded to a thermally grown oxide scale on the underlying metal surface. The “glaze” protects the coating, lowering the wear rate to ≈1 × 10−5 mm3/(N·m) and the friction coefficient to <0.45. Under high-stress particle abrasion conditions, wear rates of ≈1 × 10−3 mm3/(N·m) are found.", keywords = "Dry particles abrasion, Electrochemical corrosion test, High velocity oxygen-fuel (HVOF), High-temperature tribology, Sliding wear, Stellite coating", author = "Paolo Sassatelli and Giovanni Bolelli and {Lassinantti Gualtieri}, Magdalena and Esa Heinonen and Mari Honkanen and Luca Lusvarghi and Tiziano Manfredini and Rinaldo Rigon and Minnamari Vippola", year = "2018", month = "3", day = "25", doi = "10.1016/j.surfcoat.2018.01.078", language = "English", volume = "338", pages = "45--62", journal = "Surface & Coatings Technology", issn = "0257-8972", publisher = "Elsevier", }
@article{d58d929e58f54de4a01442959c248f03, title = "Thermal Isomerization of Hydroxyazobenzenes as a Platform for Vapor Sensing", abstract = "Photoisomerization of azobenzene derivatives is a versatile tool for devising light-responsive materials for a broad range of applications in photonics, robotics, microfabrication, and biomaterials science. Some applications rely on fast isomerization kinetics, while for others, bistable azobenzenes are preferred. However, solid-state materials where the isomerization kinetics depends on the environmental conditions have been largely overlooked. Herein, an approach to utilize the environmental sensitivity of isomerization kinetics is developed. It is demonstrated that thin polymer films containing hydroxyazobenzenes offer a conceptually novel platform for sensing hydrogen-bonding vapors in the environment. The concept is based on accelerating the thermal cis-trans isomerization rate through hydrogen-bond-catalyzed changes in the thermal isomerization pathway, which allows for devising a relative humidity sensor with high sensitivity and quick response to relative humidity changes. The approach is also applicable for detecting other hydrogen-bonding vapors such as methanol and ethanol. Employing isomerization kinetics of azobenzenes for vapor sensing opens new intriguing possibilities for using azobenzene molecules in the future.", author = "Mikko Poutanen and Zafar Ahmed and Lauri Rautkari and Olli Ikkala and Arri Priim{\"a}gi", year = "2018", month = "3", day = "20", doi = "10.1021/acsmacrolett.8b00093", language = "English", volume = "7", pages = "381--386", journal = "ACS Macro Letters", issn = "2161-1653", publisher = "American Chemical Society ACS", number = "3", }
@article{bdb48df89d9c4f8aa7c63f8893aebae2, title = "Improving the high temperature abrasion resistance of thermally sprayed Cr3C2-NiCr coatings by WC addition", abstract = "Two experimental agglomerated and sintered (a&s) feedstock powders were prepared, in order to reveal the role of WC addition on the microstructure, hardness, and the abrasion resistance of HVOF-sprayed Cr3C2-NiCr coatings. These powders contained 10 wt.{\%} of sub-micron WC, 20 or 10 wt.{\%} of nickel binder, and Cr3C2 as balance. Experimental coatings were deposited by a liquid fueled high velocity oxygen-fuel (HVOF) spray process and subsequently heat treated at 800 °C for 8 h to simulate elevated temperature service conditions. The microstructures of the powders and coatings were studied by SEM and X-ray diffraction, and the hardnesses of coatings were probed by means of micro and nanoindentation. In addition, the high stress abrasion resistance was tested in a temperature range from room temperature up to 800 °C. The microstructural characterization of the coatings displayed the presence of WC and tungsten containing Cr3C2 grains. The coating hardness increased after heat treatment, which stemmed from precipitation of secondary carbides and solid solution strengthening of the binder by tungsten. In addition, the study revealed that both experimental coatings have high wear resistance at room and elevated temperatures.", keywords = "Abrasive wear, CrC-NiCr, Hardmetal, High temperature, Thermal spray, WC", author = "Leo Janka and Berger, {Lutz Michael} and Jonas Norpoth and Richard Trache and Sven Thiele and Christian Tomastik and Ville Matikainen and Petri Vuoristo", year = "2018", month = "3", day = "15", doi = "10.1016/j.surfcoat.2018.01.035", language = "English", volume = "337", pages = "296--305", journal = "Surface & Coatings Technology", issn = "0257-8972", publisher = "Elsevier", }
@article{c4b7d1e628cc4ef7ac2bc62b5b820ae2, title = "High-performance elastomeric strain sensors based on nanostructured carbon fillers for potential tire applications", abstract = "For the development of intelligent vehicle tires, especially for future self-driving cars, suitable strain sensors are mandatory. The design of such a strain sensor must fulfil several criteria, most important of all, it must be easily mounted or implanted into the tire and the elastic nature of the sensors must be synchronized with the deformation behaviour of the tire. To our knowledge, we evaluate for the first time, the piezoresistive characteristics of a composite developed from tire rubber, taking into account the morphology (distribution and dispersion of the fillers), filler network structure, crosslinking density and the stiffness (hardness) of the rubber matrix. We use a commercially available synthetic solution polymerized styrene butadiene rubber (SSBR) which is widely used in modern car tire industries. As the internal structure of the filler particles can rearrange or alter during deformation, it is extremely important to study the piezo-resistive performance with respect to crosslinking density, hardness and modulus of the rubber composites in details. The present paper focusses on the development of strain sensors by exploiting conductive elastomeric composites based on SSBR with conducting carbon fillers like carbon black and carbon nanotubes. The sensors can be stretched to several hundred percent of their original length and a sensitivity could be achieved as much as ∼1000 (gauge factor) in a given strain regime of ∼100{\%}, while maintaining the mechanical robustness. Some of the mechanical properties like tensile strength (∼20 MPa), and modulus at 100{\%} elongation are found to be quite satisfactory indicating the suitability of the materials for real applications.", author = "Bhagavatheswaran, {Eshwaran Subramani} and Vaikuntam, {Sankar Raman} and St{\"o}ckelhuber, {Klaus Werner} and Sven Wie{\ss}ner and Gert Heinrich and Amit Das", year = "2018", month = "3", day = "1", doi = "10.1016/j.mtcomm.2018.01.013", language = "English", volume = "14", pages = "240--248", journal = "Materials Today Communications", issn = "2352-4928", publisher = "Elsevier BV", }
@article{69ef8d0291e54be2aed5a9127ec313f5, title = "Soft hydrazone crosslinked hyaluronan- and alginate-based hydrogels as 3D supportive matrices for human pluripotent stem cell-derived neuronal cells", abstract = "Regenerative medicine, especially cell therapy combined with a supportive biomaterial scaffold, is considered to be a potential treatment for various deficits in humans. Here, we have produced and investigated the detailed properties of injectable hydrazone crosslinked hyaluronan-polyvinyl alcohol (HA-PVA) and alginate-polyvinyl alcohol (AL-PVA) hydrogels to be used as a supportive biomaterial for 3D neural cell cultures. To the best of our knowledge, this is the first time the polymerization and properties of hydrazone crosslinked AL-PVA hydrogel have been reported. The effect of the degree of substitution and molecular weight of the polymer components as well as the polymer concentration of the hydrogel on the swelling, degradation and mechanical properties of the hydrogels is reported. Furthermore, we studied the effect of the above parameters on the growth of human pluripotent stem cell-derived neuronal cells. The most neural cell supportive HA-PVA hydrogel was composed of high molecular weight HA component with brain-mimicking mechanical properties and decreased polymer concentration. AL-PVA hydrogel, with stiffness quite similar to brain tissue, was also shown to be similarly supportive. Neuronal spreading and 3D network formation was enhanced inside the softest hydrogels.", keywords = "3D neuronal culture, Alginate, Hyaluronan, Hydrazone, Hydrogel", author = "Jennika Karvinen and Tiina Joki and Laura Yl{\"a}-Outinen and Koivisto, {Janne T.} and Susanna Narkilahti and Minna Kellom{\"a}ki", year = "2018", month = "3", day = "1", doi = "10.1016/j.reactfunctpolym.2017.12.019", language = "English", volume = "124", pages = "29--39", journal = "Reactive and Functional Polymers", issn = "1381-5148", publisher = "Elsevier Science B.V.", }
@article{1b45d6d48cb64a9790b20cbc93fb0eea, title = "Improved Stability of Atomic Layer Deposited Amorphous TiO2 Photoelectrode Coatings by Thermally Induced Oxygen Defects", abstract = "Amorphous titanium dioxide (a-TiO2) combined with an electrocatalyst has shown to be a promising coating for stabilizing traditional semiconductor materials used in artificial photosynthesis for efficient photoelectrochemical solar-to-fuel energy conversion. In this study we report a detailed analysis of two methods of modifying an undoped thin film of atomic layer deposited (ALD) a-TiO2 without an electrocatalyst to affect its performance in water splitting reaction as a protective photoelectrode coating. The methods are high-temperature annealing in ultrahigh vacuum and atomic hydrogen exposure. A key feature in both methods is that they preserve the amorphous structure of the film. Special attention is paid to the changes in the molecular and electronic structure of a-TiO2 induced by these treatments. On the basis of the photoelectrochemical results, the a-TiO2 is susceptible to photocorrosion but significant improvement in stability is achieved after heat treatment in vacuum at temperatures above 500 °C. On the other hand, the hydrogen treatment does not increase the stability despite the ostensibly similar reduction of a-TiO2. The surface analysis allows us to interpret the improved stability to the thermally induced formation of O- species within a-TiO2 that are essentially electronic defects in the anionic framework.", author = "Markku Hannula and Harri Ali-L{\"o}ytty and Kimmo Lahtonen and Essi Sarlin and Jesse Saari and Mika Valden", year = "2018", month = "2", day = "27", doi = "10.1021/acs.chemmater.7b02938", language = "English", volume = "30", pages = "1199--1208", journal = "Chemistry of Materials", issn = "0897-4756", publisher = "American Chemical Society", number = "4", }
@article{a3ac665444ff4b0fafde53f0d560c6f6, title = "Entrapped Styrene Butadiene Polymer Chains by Sol-Gel-Derived Silica Nanoparticles with Hierarchical Raspberry Structures", abstract = "A sol-gel transformation of liquid silica precursor to solid silica particles was carried out in a one-pot synthesis way, where a solution of styrene butadiene elastomer was present. The composites, thus produced, offered remarkable improvements of mechanical and dynamic mechanical performances compared to precipitated silica. The morphological analysis reveals that the alkoxy-based silica particles resemble a raspberry structure when the synthesis of the silica was carried out in the presence of polymer molecules and represent a much more open silica-network structure. However, in the absence of the polymer, the morphology of the silica particles is found to be different. It is envisaged that the special morphology of the in situ synthesized silica particles contributes to the superior reinforcement effects, which are associated with a strong silica-rubber interaction by rubber chains trapped inside the raspberry-like silica aggregates. Therefore, the interfaces are characterized in detail by low-field solid-state 1H NMR spectroscopy, 29Si solid-state NMR spectroscopy, and energy-dispersive X-ray spectroscopy. Low-field 1H NMR-based double-quantum experiments provide a quantitative information about the cross-link density of the silica-filled rubber composites and about the influence of silane coupling agent on the chemical cross-link density of the network and correlates well with equilibrium swelling measurements. The special microstructure of the alkoxy-based silica was found to be associated with the interaction between alkoxy-based silica and rubber chains as a consequence of particle growth in the presence of rubber chains.", author = "Vaikuntam, {Sankar Raman} and St{\"o}ckelhuber, {Klaus Werner} and {Subramani Bhagavatheswaran}, Eshwaran and Sven Wie{\ss}ner and Ulrich Scheler and Kay Saalw{\"a}chter and Petr Formanek and Gert Heinrich and Amit Das", year = "2018", month = "2", day = "15", doi = "10.1021/acs.jpcb.7b11792", language = "English", volume = "122", pages = "2010--2022", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "6", }
@article{1d3d1712932f4d048c0b307427fee031, title = "Arc-sprayed Fe-based coatings from coredwires for wear and corrosion protection in power engineering", abstract = "High wear and corrosion of parts lead to an increase in operating costs at thermal power plants. The present paper shows a possible solution to this problem through the arc spraying of protective coatings. Cored wires of the base alloying system Fe-Cr-C were used as a feedstock. Rise of wear- and heat-resistance of the coatings was achieved by additional alloying with Al, B, Ti, and Y. The wear and heat resistance of the coatings were tested via a two-body wear test accompanied by microhardness measurement and the gravimetric method, respectively. A high-temperature corrosion test was performed at 550 °C under KCl salt deposition. The porosity and adhesion strengths of the coatings were also evaluated. The microstructure was investigated with a scanning electron microscope (SEM) unit equipped with an energy dispersive X-ray (EDX) microanalyzer, and the phase composition was assessed by X-ray diffractometry. The test results showed the positive influence of additional alloying with Y on the coating properties. A comparison with commercial boiler materials showed that the coatings have the same level of heat resistance as austenite steels and are an order of magnitude higher than that of pearlite and martensite-ferrite steels. The coatings can be applied to wear- and heat-resistant applications at 20-700 °C.", keywords = "Adhesion, Arc spraying, Coating, Cored wire, Waste-to-energy boilers, Wear and corrosion resistance", author = "Korobov Yury and Michael Filippov and Aleksey Makarov and Irina Malygina and Natalia Soboleva and Davide Fantozzi and Milanti Andrea and Heli Koivuluoto and Petri Vuoristo", year = "2018", month = "2", day = "1", doi = "10.3390/coatings8020071", language = "English", volume = "8", journal = "Coatings", issn = "2079-6412", publisher = "MDPI", number = "2", }
@article{407229a746ba47c5836ead860cd4a7bb, title = "Ortho-Fluorination of azophenols increases the mesophase stability of photoresponsive hydrogen-bonded liquid crystals", abstract = "Photoresponsive liquid crystals (LCs) whose alignment can be controlled with UV-Visible light are appealing for a range of photonic applications. From the perspective of exploring the interplay between the light response and the self-assembly of the molecular components, supramolecular liquid crystals are of particular interest. They allow elaborating the structure-property relationships that govern the optical performance of LC materials by subtle variation of the chemical structures of the building blocks. Herein we present a supramolecular system comprising azophenols and stilbazoles as hydrogen-bond donors and acceptors, respectively, and show that ortho-fluorination of the azophenol dramatically increases the thermal stability of the LC phases, an important characteristics in their further utilization in photonics. The systems exhibit fast photoinduced order-disorder transitions, and rapid recovery of the liquid-crystalline state once the light irradiation is ceased, due to the photochemical properties of azophenols.", author = "Marco Saccone and Kim Kuntze and Zafar Ahmed and Antti Siiskonen and Michael Giese and Arri Priimagi", year = "2018", month = "1", day = "1", doi = "10.1039/c8tc02611d", language = "English", volume = "6", pages = "9958--9963", journal = "Journal of Materials Chemistry C", issn = "2050-7526", publisher = "Royal Society of Chemistry", number = "37", }
@inproceedings{2be5be71356b4a2283f82aeda93cf7ff, title = "Process time importance in the product properties evolvement during extrusion coating of different LDPE grades", abstract = "Process time in air gap region is one of the most important variables in the coating property development, when the molten polymer is moving from the die exit into the nip region in extrusion coating. Coating property evolvement of different LDPE grades are presented in the paper. The importance of the throughput rate and line speed to the process times is discussed by considering the effect of molecular structure of different polyolefins. The draw down ratio based on the grammage measurements is proposed to use in the practical situations.", author = "E. Suokas and J. Kuusipalo", year = "2018", month = "1", day = "1", language = "English", pages = "151--159", booktitle = "15th TAPPI Advanced Coating Fundamentals Symposium 2018", publisher = "TAPPI Press", address = "United States", }
@article{b031b6e721574faaa902e3cb0e0472be, title = "Better understanding of the role of SiO2, P2O5 and Al2O3 on the spectroscopic properties of Yb3+ doped silica sol-gel glasses", abstract = "Yb3+ doped silica sol-gel glass powders were prepared with different concentrations of SiO2, Al2O3 and P2O5 in order to understand the impact of the glass composition on the Yb3+ emission properties. In this paper, we clearly show that not only the Al/P ratio but also the SiO2 content have an impact on the Yb3+ spectroscopic properties. Our results provide new insight on the real impact of the composition on the spectroscopic properties of Yb3+ doped sol-gels: we demonstrate that an increase in the Al2O3 content at the expense of P2O5 leads to an increase in the intensity of the emission at 1000nm of the Yb3+ ions whereas an increase in the SiO2 content decreases it. We clearly showed that the inexpensive sol-gel approach can be easily used when investigating new Yb3+ doped silica glasses.", keywords = "Silica glass, Sol-gel, Spectroscopic properties, Yb doping", author = "Benoit Glorieux and Turkka Salminen and Jonathan Massera and Mika Lastusaari and Laeticia Petit", year = "2018", doi = "10.1016/j.jnoncrysol.2017.12.021", language = "English", volume = "482", pages = "46--51", journal = "Journal of Non-Crystalline Solids", issn = "0022-3093", publisher = "Elsevier", }
@article{de97d6bbca7c44fe9926dbb170abe323, title = "Convenient extraction method for quantification of thin zinc patina layers", abstract = "Synthetic zinc patina was grown on galvanized steel sheets in supercritical carbon dioxide atmosphere. Different patina compounds were dissolved and quantified using a stepwise immersion and dissolution procedure. The distinct patina components, namely anhydrous zinc carbonate (a dense layer adjacent to metallic zinc) and zinc hydroxy carbonate (nanowires on the surface), were dissolved in glycine solutions, followed by quantification of Zn2+ in the solutes by X-ray fluorescence. The zinc hydroxy carbonate nanowires were readily glycine soluble, and the anhydrous zinc carbonate showed scarce glycine solubility, which enabled their selective quantification. The amount of the remaining (anhydrous) zinc carbonate after glycine extraction was determined from the glycine-soluble zinc oxide after calcination (heat treatment for 10 minutes at 350°C). The results were verified by scanning electron microscopy imaging and Fourier transform infrared spectroscopy measurements.", keywords = "Galvanized steel, Glycine, Supercritical carbon dioxide, Zinc carbonate, Zinc nanowires, Zinc oxide", author = "Ville Saarimaa and Aaretti Kaleva and Teemu Paunikallio and Juha-Pekka Nikkanen and Saara Heinonen and Erkki Lev{\"a}nen and Pasi V{\"a}is{\"a}nen and Antti Markkula", year = "2018", doi = "10.1002/sia.6429", language = "English", volume = "50", pages = "564--570", journal = "Surface and Interface Analysis", issn = "0142-2421", publisher = "Wiley", number = "5", }
@article{904272df1c0f409194a423ebfc8a49e9, title = "Efficient photon upconversion at remarkably low annihilator concentrations in a liquid polymer matrix: when less is more", abstract = "A green-to-blue triplet-triplet annihilation upconversion of 24.5{\%} quantum yield was achieved at a remarkably low 600 μM annihilator concentration in a viscous polymer matrix. This was made possible by utilizing a ZnTPP-based photosensitizer with exceptionally long 11 ms phosphorescence lifetime. Higher 3 mM annihilator concentration resulted in lower 24{\%} upconversion quantum yield.", keywords = "triplet-triplet annihilation, triplet-triplet energy transfer, triplet state lifetime, upconversion, triplet fusion", author = "Durandin, {Nikita A.} and Jussi Isokuortti and Alexander Efimov and Elina Vuorimaa-Laukkanen and Tkachenko, {Nikolai V.} and Timo Laaksonen", year = "2018", doi = "10.1039/c8cc07592a", language = "English", volume = "54", pages = "14029--14032", journal = "Chemical Communications", issn = "1359-7345", publisher = "ROYAL SOC CHEMISTRY", number = "99", }
@article{a0388827b5dc4606bdbd4667edf937af, title = "Evaluating the toughness of APS and HVOF-sprayed Al2O3-ZrO2-coatings by in-situ- and macroscopic bending", abstract = "Thermally-sprayed ceramic coatings are commonly used in applications where high wear and corrosion resistance are essential. However, their inherently low toughness and resistance to impacts often limit their use. In bulk ceramics, the toughening effect of ZrO2 has been successfully implemented in different compositions of Al2O3-ZrO2. Successful toughening leads to increased wear resistance and higher reliability. In this study, APS- and HVOF-sprayed Al2O3-40ZrO2 coatings were characterized with SEM and XRD techniques. The toughness of the coatings was evaluated by measuring their strain tolerance with in-situ (SEM) three-point-bending and macroscopic four-point bending with acoustic emission instrumentation. The APS-coatings had a higher strain-to-fracture but failed abruptly. In HVOF-coatings, the cracking commenced earlier but proceeded slower with more crack deflections. The observed behaviour is likely to derive from the coarser microstructure of the APS-coatings, which allows strain distribution in a larger area unlike the finer structure with a lesser melting degree of the HVOF-coatings.", keywords = "AlO-ZrO, Fracture, Mechanical testing, Thermal spray, Toughening", author = "J. Kiilakoski and R. Musalek and F. Lukac and H. Koivuluoto and P. Vuoristo", year = "2018", doi = "10.1016/j.jeurceramsoc.2017.11.056", language = "English", volume = "38", pages = "1908--1918", journal = "Journal of the European Ceramic Society", issn = "0955-2219", publisher = "Elsevier", number = "4", }
@article{d71ff3d66bf6429980b61f263e88a4ed, title = "Improved electromechanical response in acrylic rubber by different carbon-based fillers", abstract = "Dielectric elastomers are materials often utilized for the fabrication of electroactive actuators. Acrylic rubber (ACM) is very widely used in dielectric elastomer actuators (DEAs). However, its overall good performance is limited by the high operating electric field required. In the present work, we compare the effect of different types of conventionally used carbon black (CB) as well as other carbon-based fillers on the dielectric and actuation properties of ACM in order to show that performance of DEAs can be improved by the development of ACM composites. Indeed, addition of CB, carbon nanotubes (CNTs), and synthetic graphite leads to an increase in the relative dielectric permittivity of elastomeric material. Moreover, incorporation of nanodiamonds results in reduction of dielectric losses. Finally, actuation stress is remarkably improved by CNTs and different grades of CB.", author = "Alexandra Shakun and Minna Poikelisp{\"a}{\"a} and Amit Das and Jyrki Vuorinen", year = "2018", doi = "10.1002/pen.24586", language = "English", volume = "58", pages = "395--404", journal = "Polymer Engineering and Science", issn = "0032-3888", publisher = "Wiley", number = "3", }
@article{45fda60a32154c60b840b4cebc2d0da1, title = "Modification of epoxy resin by silane-coupling agent to improve tensile properties of viscose fabric composites", abstract = "The modification of epoxy resin by 3-aminopropyltriethoxysilane (APTES) to improve the tensile properties of warp knitted viscose fabric composites is reported in this study. The study evaluates the efficiency of modification methods adopted to modify the epoxy resin and the influence of the resin modification on various properties of the cured castings. The influence of matrix resin modification on the tensile properties of viscose fabric composite is compared to those prepared from chemically modified fibre. The efficiency of the modification was determined through titration method to determine the epoxide content of epoxy resin, viscosity measurement and FTIR. The effect of APTES modification on various properties of cured castings is studied through differential scanning calorimeter, contact angle measurement and tensile testing. The addition of APTES into the epoxy resin decreased the epoxide content in the resin as evident from the titration method. The tensile strength of cured castings decreased after the resin modification. The tensile strength and elongation at break of the viscose fabric composites prepared from modified resin, increased up to 14 and 41{\%}, respectively. The improved adhesion of APTES-modified epoxy resin to the viscose fibre is confirmed from SEM analysis of tensile fracture surface.", keywords = "APTES, Composites, Epoxy, Modification, Regenerated cellulose, Silane coupling agent, Tensile, Viscose", author = "Rathish Rajan and Egidija Rainosalo and Thomas, {Selvin P.} and Ramamoorthy, {Sunil Kumar} and Janez Zavašnik and Jyrki Vuorinen and Mikael Skrifvars", note = "EXT={"}Skrifvars, Mikael{"}", year = "2018", doi = "10.1007/s00289-017-2022-2", language = "English", volume = "75", pages = "167–195", journal = "Polymer Bulletin", issn = "0170-0839", publisher = "Springer Verlag", number = "1", }
@article{e5fb19c01a2f4e8d88df05e52c721385, title = "Novel Online Diagnostic Analysis for In-Flight Particle Properties in Cold Spraying", abstract = "In cold spraying, powder particles are accelerated by preheated supersonic gas stream to high velocities and sprayed on a substrate. The particle velocities depend on the equipment design and process parameters, e.g., on the type of the process gas and its pressure and temperature. These, in turn, affect the coating structure and the properties. The particle velocities in cold spraying are high, and the particle temperatures are low, which can, therefore, be a challenge for the diagnostic methods. A novel optical online diagnostic system, HiWatch HR, will open new possibilities for measuring particle in-flight properties in cold spray processes. The system employs an imaging measurement technique called S-PTV (sizing-particle tracking velocimetry), first introduced in this research. This technique enables an accurate particle size measurement also for small diameter particles with a large powder volume. The aim of this study was to evaluate the velocities of metallic particles sprayed with HPCS and LPCS systems and with varying process parameters. The measured in-flight particle properties were further linked to the resulting coating properties. Furthermore, the camera was able to provide information about variations during the spraying, e.g., fluctuating powder feeding, which is important from the process control and quality control point of view.", keywords = "cold spraying, diagnostics, in-flight properties, particle size, particle velocity", author = "Heli Koivuluoto and Ville Matikainen and Jussi Larjo and Petri Vuoristo", year = "2018", doi = "10.1007/s11666-018-0685-3", language = "English", volume = "27", pages = "423–432", journal = "Journal of Thermal Spray Technology", issn = "1059-9630", publisher = "ASM International", number = "3", }
@article{0b019c45c8e44bf99e2d1a513c6cc8d4, title = "Persistent luminescent particles containing bioactive glasses: Prospect toward tracking in-vivo implant mineralization using biophotonic ceramics", abstract = "In this paper, we demonstrate that persistent luminescent bodies can be obtained by carefully choosing the sintering temperatures and duration. A borosilicate and a phosphate glasses were sintered into bodies with persistent luminescent (PeL) SrAl2O4:Eu2+,Dy3+ microparticles which have a green emission up to tens of hours after ceasing irradiation. When sintered at high temperature for a short time or at lower temperature for a longer time, a decrease in the PeL from the bodies was observed and was related to the glasses crystallization. A decrease in the PeL from the bodies was also observed after immersion in simulated body fluid and was related to the mineralization of the sintered bodies. Therefore, we clearly show that by tracking the changes in the PeL overtime, these PeL bodies have a real potential application as biophotonic sensors to track dissolution and mineralization of the implant in the body.", keywords = "Bioactivity, Biophotonic, Conventional luminescence, Microparticles containing glasses, Persistent luminescence, Sintering process", author = "M. Saarinen and A. Nommeots-Nomm and M. Hokka and J. Laurila and I. Norrbo and M. Lastusaari and J. Massera and L. Petit", year = "2018", doi = "10.1016/j.jeurceramsoc.2017.08.024", language = "English", volume = "38", pages = "287--295", journal = "Journal of the European Ceramic Society", issn = "0955-2219", publisher = "Elsevier", number = "1", }
@article{be75957c793043608c33676fd324c7af, title = "Simultaneous removal of tetrathionate and copper from simulated acidic mining water in bioelectrochemical and electrochemical systems", abstract = "This study demonstrates (bio)electrochemical tetrathionate (S4O6 2 −) degradation with simultaneous elemental copper recovery from simulated acidic mining water. The effect of applied external voltage on anodic tetrathionate removal, cathodic copper removal and current density was studied using two-chamber flow-through bioelectrochemical (MEC) and abiotic electrochemical (EC) systems. At low applied cell voltages (≤ 0.5 V), the highest tetrathionate removal rate (150–170 mg L− 1 d− 1) and average current density (15–30 mA m− 2) was obtained with MEC. At applied external voltages above 0.75 V, abiotic EC provided the highest average current density (410–3600 mA m− 2). In bioelectrochemical systems, the current generation likely proceeds via intermediary reaction products (sulfide and/or thiosulfate), while in electrochemical system tetrathionate is oxidized directly on the electrode. The copper removal rates remained low (< 10 mg L− 1 d− 1) in all systems at applied cell voltages below 0.5 V, but increased up to a maximum of 440 mg L− 1 d− 1 in MEC and to 450 mg L− 1 d− 1 in EC at applied cell voltage of 1.5 V. After seven days of operation at applied cell voltage of 1.5 V, copper removal efficiency was 99.9{\%} in both MEC and EC and the average tetrathionate removal rates were 160 mg L− 1 d− 1 and 190 mg L− 1 d− 1, respectively. This study shows that by applying external voltage, tetrathionate and copper can be efficiently removed from acidic waters with bioelectrochemical and electrochemical systems.", keywords = "Bioelectrochemical system, Copper removal, Electrochemical system, Reduced inorganic sulfur compound, Tetrathionate", author = "Sulonen, {Mira L.K.} and Kokko, {Marika E.} and Aino-Maija Lakaniemi and Puhakka, {Jaakko A.}", year = "2018", doi = "10.1016/j.hydromet.2018.01.023", language = "English", volume = "176", pages = "129--138", journal = "Hydrometallurgy", issn = "0304-386X", publisher = "Elsevier", }
@article{c38bf7099058446da10b467a4ad5e997, title = "Stable blue phase polymeric Langmuir-Schaefer films based on unsymmetrical hydroxyalkadiynyl N-arylcarbamate derivatives", abstract = "Unsymmetrical diynes containing N-arylcarbamate groups in the hydrophobic part and hydroxymethylene groups in the hydrophilic part of the molecules were synthesized and studied. The Langmuir monolayer formation process was followed by Brewster angle microscopy (BAM). The Langmuir-Schaefer monolayer films, transferred on solid substrates (quartz or Si), were investigated by absorption spectroscopy and atomic force microscopy (AFM). Four substances had 2 methylene groups in the hydrophilic part of the molecule (n) and 4 or 5 of these groups in the hydrophobic part (m). At the same time the aryl substituent had a hydrogen atom or a MeO group in the p-position of the benzene ring. After 20 min of UV irradiation the initially colorless monomeric films of all four compounds turned into stable blue phase polymeric films. The blue phase is unusual for alcoholic diacetylene derivatives. The BAM and AFM measurements demonstrated higher homogeneity of the films with a MeO group in the aryl substituent in comparison to the molecules with a hydrogen atom. The reasons for these different structural organizations as well as potential applications of stable blue phase polydiacetylene thin films are discussed.", keywords = "Absorption spectroscopy, Blue phase polydiacetylenes, Brewster angle microscopy, Langmuir-Schaefer film, Photopolymerization", author = "Alexander Alekseev and Petri Ihalainen and Artem Ivanov and Ivan Domnin and Emil Rosqvist and Helge Lemmetyinen and Elina Vuorimaa-Laukkanen and Jouko Peltonen and Sergey Vyaz'min", note = "EXT={"}Alekseev, Alexander{"}", year = "2018", doi = "10.1016/j.tsf.2017.10.018", language = "English", volume = "645", pages = "108--118", journal = "Thin Solid Films", issn = "0040-6090", publisher = "Elsevier", }
@article{450dd891fd544bae88518ed685d0bb02, title = "Supramolecular design principles for efficient photoresponsive polymer-azobenzene complexes", abstract = "Noncovalent binding of azobenzenes to polymers allows harnessing light-induced molecular-level motions (photoisomerization) for inducing macroscopic effects, including photocontrol over molecular alignment and self-assembly of block copolymer nanostructures, and photoinduced surface patterning of polymeric thin films. In the last 10 years, a growing body of literature has proven the utility of supramolecular materials design for establishing structure-property-function guidelines for photoresponsive azobenzene-based polymeric materials. In general, the bond type and strength, engineered by the choice of the polymer and the azobenzene, influence the photophysical properties and the optical response of the material system. Herein, we review this progress, and critically assess the advantages and disadvantages of the three most commonly used supramolecular design strategies: hydrogen, halogen and ionic bonding. The ease and versatility of the design of these photoresponsive materials makes a compelling case for a paradigm shift from covalently-functionalized side-chain polymers to supramolecular polymer-azobenzene complexes.", author = "Jaana Vapaavuori and Bazuin, {C. Geraldine} and Arri Priimagi", year = "2018", doi = "10.1039/c7tc05005d", language = "English", volume = "6", pages = "2168--2188", journal = "Journal of Materials Chemistry C", issn = "2050-7526", publisher = "Royal Society of Chemistry", number = "9", }
@article{24f55ca28058487aaf81015ab3c41353, title = "Tribology of FeVCrC coatings deposited by HVOF and HVAF thermal spray processes", abstract = "This work studies FeVCrC-based coatings as potential alternatives to conventional Ni- and Co-based alloys for wear protection. Specifically, the microstructure and tribological properties of the coatings are characterized as a function of the particle size distribution of the feedstock powder, of the deposition technique – High Velocity Oxygen-Fuel (HVOF) or High Velocity Air-Fuel (HVAF) spraying – and of specific processing parameters. HVOF-sprayed coatings obtained from fine feedstock powder exhibit numerous oxide inclusions, which provide high hardness (≈ 900 HV0.3) but do not excessively impair fracture toughness, as determined through scratch testing techniques. HVAF-sprayed coatings obtained from the same feedstock powder contain much fewer oxide inclusions, and some of them possess simultaneously high hardness and high toughness. Defects (e.g. speckles) are instead formed in case unsuitable HVAF torch hardware is employed. A coarse feedstock powder always results in unmelted inclusions, which impair the cohesion of the coatings, particularly of the HVAF-sprayed ones. Most coatings anyway exhibit very low sliding wear rates < 3 × 10−6 mm3/(N m); abrasive grooving and surface fatigue-induced pitting are the main wear mechanisms. Oxide inclusions do not affect negatively the response of HVOF coatings, whereas too many unmolten particles increase pitting under severe test conditions. Rubber-wheel abrasion testing produces comparatively more severe grooving.", keywords = "Coating: thermal spray coatings, Hardness, Sliding wear, Two-body abrasion", author = "Giovanni Bolelli and Marcello Bursi and Luca Lusvarghi and Tiziano Manfredini and Ville Matikainen and Rinaldo Rigon and Paolo Sassatelli and Petri Vuoristo", year = "2018", doi = "10.1016/j.wear.2017.10.014", language = "English", volume = "394-395", pages = "113--133", journal = "Wear", issn = "0043-1648", publisher = "Elsevier", }
@article{1a66fe5e8b9c48059c2b65c2c0fd1295, title = "Supercritical carbon dioxide treatment of hot dip galvanized steel as a surface treatment before coating", abstract = "Supercritical carbon dioxide (scCO2) treatment was employed for rapid formation of a zinc patina layer on hot dip galvanized (HDG) steel. In the presence of H2O and a Cu precursor, an artificial patina consisting of two distinctive phases was formed: a dense ~ 1 μm layer of anhydrous ZnCO3 adjacent to native zinc coating, and a needle-like porous structure showing resemblance to hydrozincite (Zn5(CO3)2(OH)6). The artificial patina layer significantly decreased the surface free energy of HDG, which was evidenced also by good wettability by a polyester melamine coating. Furthermore, the needle-like patina surface structure stayed intact through the coating process, indicating improved coating adhesion. ScCO2 treatment facilitates rapid and impurity-free surface treatment of hot dip galvanized steel, and could be used to tailor novel adhesion and corrosion promoting surface morphologies.", keywords = "Basic zinc carbonate, Coatings, Corrosion resistance, Hot dip galvanized steel, Patina, Supercritical carbon dioxide, Zinc", author = "Ville Saarimaa and Aaretti Kaleva and Juha-Pekka Nikkanen and Saara Heinonen and Erkki Lev{\"a}nen and Pasi V{\"a}is{\"a}nen and Antti Markkula and Jyrki Juhanoja", year = "2017", month = "12", day = "15", doi = "10.1016/j.surfcoat.2017.10.047", language = "English", volume = "331", pages = "137--142", journal = "Surface & Coatings Technology", issn = "0257-8972", publisher = "Elsevier", }
@article{ad4074ab875847258d6e8081e2a2cefc, title = "Time-Resolved Fluorescence Spectroscopy Reveals Fine Structure and Dynamics of Poly(l-lysine) and Polyethylenimine Based DNA Polyplexes", abstract = "Structural dynamics of the polyethylenimine-DNA and poly(l-lysine)-DNA complexes (polyplexes) was studied by steady-state and time-resolved fluorescence spectroscopy using the fluorescence resonance energy transfer (FRET) technique. During the formation of the DNA polyplexes, the negative phosphate groups (P) of DNA are bound by the positive amine groups (N) of the polymer. At N/P ratio 2, nearly all of the DNA's P groups are bound by the polymer N groups: These complexes form the core of the polyplexes. The excess polymer, added to this system to increase the N/P ratio to the values giving efficient gene delivery, forms a positively charged shell around the core polyplex. We investigated whether the exchange between the core and shell regions of PEI and PLL polyplexes takes place. Our results demonstrated a clear difference between the two studied polymers. Shell PEI can replace PEIs previously attached to DNA in the polyplex core, while PLL cannot. Such a dynamic structure of PEI polyplexes compared to a more static one found for PLL polyplexes partially explains the observed difference in the DNA transfection efficiency of these polyplexes. Moreover, the time-resolved fluorescence spectroscopy revealed additional details on the structure of PLL polyplexes: In between the core and shell, there is an intermediate layer where both core and shell PLLs or their parts overlap.", author = "Lisitsyna, {Ekaterina S.} and Tiia-Maaria Ketola and Emmanuelle Morin-Picardat and Huamin Liang and Martina Hanzl{\'i}kov{\'a} and Arto Urtti and Marjo Yliperttula and Elina Vuorimaa-Laukkanen", year = "2017", month = "12", day = "7", doi = "10.1021/acs.jpcb.7b08394", language = "English", volume = "121", pages = "10782--10792", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "48", }
@article{2459af9b90f1419db8ae54f00411b680, title = "Oxygen and water vapor transmission rates of starch-poly(vinyl alcohol) barrier coatings for flexible packaging paper", abstract = "Creating efficient water-borne dispersions based mainly on renewable materials for coating of flexible packaging paper was the aim of this study. The effects of an ethylene modified poly(vinyl alcohol) grade and a standard poly(vinyl alcohol) on the oxygen and water vapor barrier performance of corn starch and potato starch coatings was studied. The results showed that a coating composition with a high fraction of a renewable polymer was effective in keeping the oxygen barrier at a technically and commercially applicable level. An ethylene modified poly(vinyl alcohol) grade was found to provide lower oxygen transmission rates at high relative humidity, as compared to a standard poly(vinyl alcohol) grade. The oxygen barrier properties of blends of starch and poly(vinyl alcohol) were similar to that of the pure modified poly(vinyl alcohol) in the range from 0{\%} starch to 60{\%} starch. This was observed with both hydroxypropylated and octenyl succinate modified starch grades. The drying conditions of the mixed starch:poly(vinyl alcohol) coatings were based on drying trials with pure poly(vinyl alcohol) coatings. Drying at moderate temperatures indicated the possibility to slightly decrease water vapor transmission rate by higher drying temperature. Several secondary effects of increased drying temperature such as coating hold-out and formation of defects may also be of importance.", keywords = "Barrier coating, Drying, Oxygen transmission rate, Poly(vinyl alcohol), Starch, Water vapor transmission rate", author = "Hanna Christophliemk and Caisa Johansson and Henrik Ullsten and Lars J{\"a}rnstr{\"o}m", year = "2017", month = "12", day = "1", doi = "10.1016/j.porgcoat.2017.04.019", language = "English", volume = "113", pages = "218--224", journal = "Progress in Organic Coatings", issn = "0300-9440", publisher = "Elsevier", }
@article{5101555d1b2b44c6bbcda5eaa2d834cb, title = "Infrared Thermography as a Non-destructive Testing Solution for Thermal Spray Metal Coatings", abstract = "In this work, an infrared (IR) thermographic procedure was evaluated as a non-destructive testing tool to detect damage in thermal spray metallic coatings. As model systems, polished HVOF- and HVAF-sprayed Fe-based layers deposited onto steel plates were employed. Damage by external-object impingement was simulated through a cyclic impact-test apparatus, which induced circumferential and radial cracks across all model systems, and interface cracks of different sizes in distinct samples. Damaged and undamaged plates were bulk-heated to above 100 °C using an IR lamp; their free-convection cooling was then recorded by an IR thermocamera. The intentionally induced defects were hardly detectable in IR thermograms, due to IR reflection and artificial “hot” spots induced by residuals of transfer material from the impacting counterbody. As a micrometer-thin layer of black paint was applied, surface emissivity got homogenized and any artifacts were effectively suppressed, so that failed coating areas clearly showed up as “cold spots.” This effect was more apparent when large interface cracks occurred. Finite-element modeling proved the physical significance of the IR-thermography approach, showing that failed coating areas are cooled by surrounding air faster than they are heated by conduction from the hot substrate, which is due to the insulating effect of cracks.", keywords = "finite element modeling, high-velocity air fuel (HVAF), high-velocity oxy fuel (HVOF), impact testing, non-destructive inspection", author = "Santangelo, {Paolo E.} and Giulio Allesina and Giovanni Bolelli and Luca Lusvarghi and Ville Matikainen and Petri Vuoristo", year = "2017", month = "12", doi = "10.1007/s11666-017-0642-6", language = "English", volume = "26", pages = "1982–1993", journal = "Journal of Thermal Spray Technology", issn = "1059-9630", publisher = "ASM International", number = "8", }
@article{2043465c38d9465c9dbb255f0ad07129, title = "Erosive wear of filled vinylester composites in water and acidic media at elevated temperature", abstract = "Due to their good corrosion properties, fibre reinforced polymer composites are often used instead of metals for example in hydrometallurgical processes. However, the erosion performance of polymer composites is rather poor when compared to metals. This study focused on the effect of mineral fillers on the erosion performance of vinylester composites. The erosion rates were tested both in water and in acidic environments at high temperature. To improve the erosion performance of the filled composites in these environments, to increase the filler particle hardness was an effective method. Within similar filler materials, better adhesion to the matrix improved the erosion performance, regardless if it was achieved by adhesion promoters or better mechanical interlocking. The hardness of the matrix was found to be disadvantageous for filled composites, although for pure vinylesters higher hardness decreased erosion rate. At the high service temperature, softer matrix accommodated more deformations and better absorption of energy of the impacting erosive particles. Consequently, improved adherence of the filler particles into the matrix and slower erosion rate was observed.", keywords = "Erosion, FRP, Glass fibre, Mineral fillers, Vinylester", author = "Essi Sarlin and Meri Saarim{\"a}ki and Reija Sironen and Mari Lindgren and Sanna Siljander and Mikko Kanerva and Jyrki Vuorinen", note = "INT=mol,{"}Sironen, Reija{"} EXT={"}Lindgren, Mari{"}", year = "2017", month = "11", day = "15", doi = "10.1016/j.wear.2017.07.011", language = "English", volume = "390-391", pages = "84--92", journal = "Wear", issn = "0043-1648", publisher = "Elsevier", }
@article{a99069b0fd1945e59bcf0b0c6630a633, title = "Fluorimetric oxygen sensor with an efficient optical read-out for in vitro cell models", abstract = "This paper presents a phase fluorimetric sensor for the monitoring of the oxygen concentration in in vitro cell models. The sensing surface of the sensor consists of oxygen sensitive fluorescent dyes (platinum(II) octaethylporphyrinketone) embedded in a thin polystyrene film. In order to optimize the optical read-out scheme of the sensor, we carried out electromagnetic simulations of a fluorescently doped polystyrene film deposited on a glass-water interface. The simulation results showed highly anisotropic angular emission distribution with the maximum irradiance being at super critical angles, which attracts tailored optical designs to maximize the fluorescence collection efficiency. For this purpose, we applied an efficient optical read-out scheme based on an in-contact parabolic lens. The use of parabolic lens also facilitates confocal total internal reflection excitation from the substrate side. This makes the excitation effective and insensitive to biofouling or other optical changes in the sensing surface and, more importantly, greatly reduces the amount of excitation power radiated into the cell culture chamber. Experimental results show that when applied together with phase fluorimetric lifetime sensing, this optical scheme allows one to use thin films (", keywords = "Cardiac cells, Enhanced optical read-out, Fluorimetric oxygen sensor, in vitro cell models, PtOEPK, Thin film fluorescence", author = "Hannu V{\"a}lim{\"a}ki and Jarmo Verho and Joose Kreutzer and {Kattipparambil Rajan}, Dhanesh and Tomi Ryyn{\"a}nen and Mari Pekkanen-Mattila and Antti Ahola and Kirsi Tappura and Pasi Kallio and Jukka Lekkala", year = "2017", month = "10", day = "1", doi = "10.1016/j.snb.2017.04.182", language = "English", volume = "249", pages = "738--746", journal = "Sensors and Actuators B: Chemical", issn = "0925-4005", publisher = "Elsevier Science", }
@article{ef0ce4def448425f96fe57227ae3fc3a, title = "Starch-poly(vinyl alcohol) barrier coatings for flexible packaging paper and their effects of phase interactions", abstract = "Starch and poly(vinyl alcohol) based barrier coatings for flexible packaging papers were studied. Both octenyl succinate modified and hydroxypropylated corn and potato starches were blended with regular and ethylene modified poly(vinyl alcohol) to increase the water vapor barrier properties and enhance the flexibility of the starch coatings, in order to accomplish superior barrier performance. Phase separation between starch and poly(vinyl alcohol) was studied in detail, both in the solution and in dry draw-down coatings on paper. The barrier performance of the coated paper was evaluated with respect to water vapor transmission rate. Conditions for the creation of a thin surface layer consisting of only one of the pure polymers were identified and discussed in terms of phase separation in solution migration of poly(vinyl alcohol) to the uppermost surface layer. The phase separation promoted low water vapor transmission rates also with a rather high fraction of starch in the coatings.", keywords = "Barrier coating, PVOH, Starch, Turbidity, Viscosity, WVTR, XPS", author = "Hanna Christophliemk and Henrik Ullsten and Caisa Johansson and Lars J{\"a}rnstr{\"o}m", year = "2017", month = "10", day = "1", doi = "10.1016/j.porgcoat.2017.04.018", language = "English", volume = "111", pages = "13--22", journal = "Progress in Organic Coatings", issn = "0300-9440", publisher = "Elsevier", }
@article{9691280996c54761bf829e1da436ddf9, title = "Investigation of long-term chemical stability of structured ZnO films in aqueous solutions of varying conditions", abstract = "Nanostructured zinc oxide, ZnO, films feature attractive functional properties, but their long-term stability needs further investigation. Here, ZnO thin films with well-aligned rod-like structure were grown on stainless steel substrate. The long-term chemical stability of the ZnO films was investigated in solutions with varying pH values (3 − 11) to enhance knowledge about the durability of films in acidic and basic environments. The solubility and stability of the films in the solutions were investigated using atomic absorption spectrophotometry, scanning electron microscopy imaging and energy-dispersive X-ray spectroscopy analyses, as well as by monitoring changes in water contact angle of the films and in the pH values of the solutions. The ZnO film was found to be most stable at highest pH value, with the amount of dissolved zinc being lowest among the studied pH values and the changes observed with other characterization methods being minor compared to the samples immersed to other solutions. At the lowest pH, the film was removed rapidly from the substrate by dissolution. In solutions featuring pH values 5 and 9, the measured pH was unstable and changed constantly until it reached the value 7.2–7.6, i.e., until the equilibrium of different chemical species in the solution was achieved. These results are presented and discussed in this paper from the viewpoint of applicability of the ZnO films.", keywords = "Chemical stability, Hydrothermal synthesis, pH, Solubility, Thin film, Zinc oxide", author = "Saara Heinonen and Juha-Pekka Nikkanen and Elina Huttunen-Saarivirta and Erkki Lev{\"a}nen", year = "2017", month = "9", day = "30", doi = "10.1016/j.tsf.2017.07.055", language = "English", volume = "638", pages = "410--419", journal = "Thin Solid Films", issn = "0040-6090", publisher = "Elsevier", }
@article{baf3fc053e754d16b3f30c770934e2c5, title = "Systematic analysis of coating-substrate interactions in the presence of flow localization", abstract = "Localized deformation and cracking in a system of thermally sprayed hard metal coating overlaid on a low alloy steel is studied by means of bend testing. In-situ digital image correlation measurements are used to characterize material strain field near the coating/substrate interface. The studied substrate undergoes softening upon yielding which manifests itself as narrow bands of localized shear deformation. The measurements show that the coating cracks and the substrate shear bands interact. When the coating starts cracking during the elastic loading of the substrate, the formed cracks function as nucleation points for the shear bands. In contrast, if the coating resists cracking until the yielding of the substrate, the coating cracks and substrate shear bands form simultaneously. Based on the experiments, continuum-scale finite element model of the system is developed, validated and then used for a systematic numerical analysis of the effects of substrate shear banding on the measurement of coating properties. Based on the results of this work, three main effects can be identified. Firstly, the flow localization in the substrate can increase the measured apparent (macroscopic) surface strain of the coating, if not accounted for by using microscopic techniques. Secondly, substrate shear bands increase the interfacial loading, which may cause unexpected delamination of the coating and thus affect the evaluation of the interfacial strength. Finally, substrate shear bands affect the stress state within the coating and may thus affect the cracking morphology in the coating. Therefore, based on the results of this study, if the coating and interfacial strengths are of similar magnitude with the substrate yield strength, the possible tendency of the substrate towards flow localization should be taken into account in the analysis of the coating behavior.", keywords = "Bending, Digital image correlation, Finite element method, Hard metal coating, Interfacial strength, Shear band", author = "M. Isakov and V. Matikainen and H. Koivuluoto and M. May", year = "2017", month = "9", day = "15", doi = "10.1016/j.surfcoat.2017.05.040", language = "English", volume = "324", pages = "264--280", journal = "Surface & Coatings Technology", issn = "0257-8972", publisher = "Elsevier", }
@article{66f9143d890a4eb1913f7400b3efd576, title = "Wear of cemented tungsten carbide percussive drill–bit inserts: Laboratory and field study", abstract = "Design of the drill–bit and selection of the Cemented Tungsten Carbide (CC) grade for drill–bit inserts are crucial for efficient percussive drilling. This study presents the results of an experimental campaign executed with the aim to identify the distinctive wear mechanisms and behaviour of different CC grades. Three laboratory and one full–scale drilling tests were performed using nine CC grades with different binder contents, binder chemical compositions, mean tungsten carbide (WC) grain sizes, and grain size distributions. Wear traces found on the drill–bit inserts after the full–scale drilling test show noticeable differences depending on their position on the drill–bit. Tensile forces present on the leading edge of the inserts due to the sliding contact with rock are suspected to play a significant role. Laboratory tests performed include: (i) single impact tests using a modified Split Hopkinson Pressure Bar (SHPB) apparatus, (ii) Abrasion Value (AV) rotating disk tests, and (iii) impact abrasion (LCPC) tests. Volume loss and shape change were used as macroscopic measures of wear. Greater volume losses were found for the grades with nickel–based binders compared to those with pure cobalt binder. The use of a narrower WC grain size distribution leads to lesser volume loss in drilling and AV tests. Surface analysis of the damaged microstructure was performed using scanning electron microscope. Distinct meso–scale (few dozens of WC grain sizes) patterns of damaged microstructure zones surrounded by the intact surface were found on the surfaces of specimens after single impact test. The pattern indicates the potential influence of a non–uniform contact due to the rock roughness and internal rock heterogeneities, which is supported by the study of the rock crater roughness. Size of such zones could be seen as a certain length–scale, which determines the insert–rock contact behaviour. A specific “peeling” mechanism of material removal was observed in the full–scale drilling test, where portion of the CC microstructure fused with the rock tribofilm gets removed when that tribofilm peels off.", keywords = "Cemented tungsten carbide, Contact area, Impact abrasion, Rotary–percussive drilling, Roughness, SEM, Sliding abrasion, Split Hopkinson pressure bar, Surface deterioration mechanisms, Volume loss, Wear", author = "Dmitry Tkalich and Li, {Charlie C.} and Alexandre Kane and Afaf Saai and Dmitry Tkalich and Yastrebov, {Vladislav A.} and Mikko Hokka and Veli-Tapani Kuokkala and Maria Bengtsson and Anna From", year = "2017", month = "9", day = "15", doi = "10.1016/j.wear.2017.05.010", language = "English", volume = "386-387", pages = "106--117", journal = "Wear", issn = "0043-1648", publisher = "Elsevier", }
@article{21035d5a130b4db69705a52576efe970, title = "A Study of Cr3C2-Based HVOF- and HVAF-Sprayed Coatings: Microstructure and Carbide Retention", abstract = "The research on high-velocity air-fuel (HVAF)-sprayed Cr3C2-based materials has mostly focused on conventional Cr3C2-25NiCr composition. In this paper, two alternative compositions (Cr3C2-50NiCrMoNb and Cr3C2-37WC-18NiCoCrFe) were sprayed with high-velocity oxy-fuel (HVOF) and HVAF spray processes to evaluate the material behavior during spraying and to provide characterization of the microstructures and mechanical properties of the coatings. For comparison, coatings from the Cr3C2-25NiCr composition were sprayed with both processes. Spray diagnostics were carried out to obtain average particle velocity and temperature for each material and process combinations. The measured average in-flight particle data were 1800 °C and 700 m/s for HVOF process, and 1450 °C and 900 m/s for HVAF process. Characterization of the coating microstructures was carried out by scanning electron microscopy and X-ray diffraction. In addition, the carbon content of the feedstock powders and sprayed coatings was measured with carbon analyzer. The results show that carbide rebounding or selective deposition of particles with higher metal matrix content is the dominating reason for carbide loss during HVAF spraying, while carbide dissolution is an additional source for the HVOF spraying. Higher particle velocities and controlled temperature measured for the HVAF process produced dense coatings with improved toughness and more homogenous coating structure.", keywords = "chromium carbide, diagnostics, HVAF, HVOF, image analysis", author = "V. Matikainen and G. Bolelli and H. Koivuluoto and M. Honkanen and M. Vippola and L. Lusvarghi and P. Vuoristo", year = "2017", month = "8", doi = "10.1007/s11666-017-0578-x", language = "English", volume = "26", pages = "1--18", journal = "Journal of Thermal Spray Technology", issn = "1059-9630", publisher = "ASM International", number = "6", }
@article{2c3f9b41afaa4c47af2eee0476b7580f, title = "Configurational Disorder of Water Hydrogen-Bond Network at the Protein Dynamical Transition", abstract = "We introduce a novel strategy to quantify the disorder of extended water-water hydrogen-bond (HB) networks sampled in particle-based computer simulations. The method relies on the conformational clustering of the HB connectivity states. We successfully applied it to unveil the fine relationship among the protein dynamical transition in hydrated powder, which marks the activation of protein flexibility at Td ≈ 240 K, and the sudden increase in the configurational disorder of the water HB network enveloping the proteins. Our finding links, in the spirit of the Adam-Gibbs relationship, the diffusivity of protein atoms, as quantified by the hydrogen mean-square displacements, and the thermodynamic solvent configurational entropy.", author = "Obaidur Rahaman and Maria Kalimeri and Marina Katava and Alessandro Paciaroni and Fabio Sterpone", year = "2017", month = "7", day = "20", doi = "10.1021/acs.jpcb.7b03888", language = "English", volume = "121", pages = "6792--6798", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "28", }
@article{8bc758ed77224448bcf7ee5310795f8f, title = "Vegetable fillers for electric stimuli responsive elastomers", abstract = "Dielectric elastomer actuators (DEAs) have been studied widely in recent years for artificial muscle applications, but their implementation into production is limited due to high operating voltages required. The actuation behavior of dielectric elastomer under an applied electric field is predicted by Maxwell's pressure and thickness strain equations. According to these equations, the best electromechanical response is achieved when the relative permittivity is high and elastic modulus is low. The potential source for additives increasing the relative permittivity of rubbers can be vegetable powders that have much higher dielectric constant than common elastomers. In the present research, the dielectric and actuation properties of polyacrylate rubber (ACM) were studied after the addition of different vegetable-based fillers such as potato starch, corn starch, garlic, and paprika. The results were compared to ACM filled with barium titanate. The compounds containing vegetable fillers showed higher relative dielectric permittivity at 1 Hz frequency than the compounds containing barium titanate due to higher interfacial polarization. The actuation studies showed that lower electric fields are required to generate certain actuation forces when the starches and garlic are used in the rubber instead of barium titanate. Therefore, the vegetable-based fillers can be used to improve actuation performance of DEAs.", keywords = "biomaterials, dielectric properties, elastomers, mechanical properties, sensors and actuators", author = "Minna Poikelisp{\"a}{\"a} and Alexandra Shakun and Essi Sarlin and Amit Das and Jyrki Vuorinen", note = "INT=mol,{"}Poikelisp{\"a}{\"a}, Minna{"}", year = "2017", month = "7", day = "20", doi = "10.1002/app.45081", language = "English", volume = "134", journal = "Journal of Applied Polymer Science", issn = "0021-8995", publisher = "Wiley", number = "28", }
@article{d0b933f330944b56af9ad312c34e71a9, title = "Quench absorption coils: A quench protection concept for high-field superconducting accelerator magnets", abstract = "A quench protection concept based on coupled secondary coils is studied for inductively transferring energy out of a quenching superconducting dipole and thus limiting the peak hotspot temperature. So-called 'quench absorption coils' are placed in close proximity to the superconducting coils and are connected in series with a diode for the purpose of preventing current transformation during regular operation. During a quench, current is then transformed into the quench absorption coils so that a significant fraction of the stored magnetic energy is dissipated in the these coils. Numerical calculations are performed to determine the impact of such a concept and to evaluate the dimensions of the quench absorption coils needed to obtain significant benefits. A previously constructed 15 T Nb3Sn block coil is taken as a reference layout. Finite-element calculations are used to determine the combined inductive and thermal response of this system and these calculations are validated with a numerical model using an adiabatic approximation. The calculation results indicate that during a quench the presence of the quench absorption coils reduces the energy dissipated in the superconducting coils by 45{\%} and reduces the hotspot temperature by over 100 K. In addition, the peak resistive voltage over the superconducting coils is significantly reduced. This suggests that this concept may prove useful for magnet designs in which the hotspot temperature is a design driver.", keywords = "accelerator magnets, coupled secondary coil, quench protection, superconductivity", author = "M. Mentink and T Salmi", year = "2017", month = "5", day = "3", doi = "10.1088/1361-6668/aa6678", language = "English", volume = "30", journal = "Superconductor Science and Technology", issn = "0953-2048", publisher = "IOP Publishing", number = "6", }
@article{cd4060f6140a43c99e91c4c849e3dd1d, title = "Halogen bonding stabilizes a cis-azobenzene derivative in the solid state: A crystallographic study", abstract = "Crystals of trans- and cis-isomers of a fluorinated azobenzene derivative have been prepared and characterized by single-crystal X-ray diffraction. The presence of F atoms on the aromatic core of the azobenzene increases the lifetime of the metastable cis-isomer, allowing single crystals of the cis-azobenzene to be grown. Structural analysis on the cis-azobenzene, complemented with density functional theory calculations, highlights the active role of the halogen-bond contact (N...I synthon) in promoting the stabilization of the cis-isomer. The presence of a long aliphatic chain on the azobenzene unit induces a phase segregation that stabilizes the molecular arrangement for both the trans- and cis-isomers. Due to the rarity of cis-azobenzene crystal structures in the literature, our paper makes a step towards understanding the role of non-covalent interactions in driving the packing of metastable azobenzene isomers. This is expected to be important in the future rational design of solid-state, photoresponsive materials based on halogen bonding. We show by single-crystal X-ray diffraction studies and computational analysis that halogen bonding can stabilize a metastable cis-azobenzene derivative in the solid state.", keywords = "azobenzene, halogen bonding, isomerization", author = "Marco Saccone and Antti Siiskonen and Franisco Fernandez-Palacio and Arri Priim{\"a}gi and Giancarlo Terraneo and Giuseppe Resnati and Pierangelo Metrangolo", year = "2017", month = "4", day = "1", doi = "10.1107/S2052520617003444", language = "English", volume = "73", pages = "227--233", journal = "ACTA CRYSTALLOGRAPHICA SECTION B : STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS", issn = "2052-5192", publisher = "International Union of Crystallography", number = "2", }
@article{64349166d216410cab3a28428b606590, title = "Effect of the addition of Al2O3, TiO2 and ZnO on the thermal, structural and luminescence properties of Er3+-doped phosphate glasses", abstract = "Er-doped phosphate glasses were fabricated by melt-quenching technique. The changes in their thermal, structural and luminescence properties with the addition of Al2O3, TiO2 or ZnO were studied. Physical and thermal properties were investigated through density measurement and differential thermal analysis. Structural characterization was performed using the Raman and Infrared spectroscopy. In order to study the influence of the composition on the luminescence properties of the glasses, the refractive index, the luminescence spectra and the lifetime values were measured. The results show that with the addition of Al2O3 and TiO2 the phosphate network becomes more connected increasing the glass transition temperature, whereas the addition of ZnO does not show significant changes in the optical, thermal and structural properties but it leads to a larger emission cross-section at 1540 nm as compared to the other glasses. As the site of the Er3+ is not strongly affected by the change in the glass composition, we think that the emission properties of the glasses depend on the glass structure connectivity, which has an impact on the Er3+ ions solubility.", keywords = "Er luminescence property, Infrared spectroscopy, Phosphate glass, Raman spectroscopy", author = "Pablo Lopez-Iscoa and Laeticia Petit and Jonathan Massera and Davide Janner and Boetti, {Nadia G.} and Diego Pugliese and Sonia Fiorilli and Chiara Novara and Fabrizio Giorgis and Daniel Milanese", year = "2017", month = "3", day = "15", doi = "10.1016/j.jnoncrysol.2017.01.030", language = "English", volume = "460", pages = "161--168", journal = "Journal of Non-Crystalline Solids", issn = "0022-3093", publisher = "Elsevier", }
@article{909b70b814a0455fa1bb982dbc0a3d81, title = "Hierarchical Self-Assembly of Halogen-Bonded Block Copolymer Complexes into Upright Cylindrical Domains", abstract = "Self-assembly of block copolymers into well-defined, ordered arrangements of chemically distinct domains is a reliable strategy for preparing tailored nanostructures. Microphase separation results from the system, minimizing repulsive interactions between dissimilar blocks and maximizing attractive interactions between similar blocks. Supramolecular methods have also achieved this separation by introducing small-molecule additives binding specifically to one block by noncovalent interactions. Here, we use halogen bonding as a supramolecular tool that directs the hierarchical self-assembly of low-molecular-weight perfluorinated molecules and diblock copolymers. Microphase separation results in a lamellar-within-cylindrical arrangement and promotes upright cylindrical alignment in films upon rapid casting and without further annealing. Such cylindrical domains with internal lamellar self-assemblies can be cleaved by solvent treatment of bulk films, resulting in separated and segmented cylindrical micelles stabilized by halogen-bond-based supramolecular crosslinks. These features, alongside the reversible nature of halogen bonding, provide a robust modular approach for nanofabrication.", keywords = "block copolymers, halogen bond, hierarchical self-assembly, nanofabrication, supramolecular complexes", author = "Roberto Milani and Nikolay Houbenov and Francisco Fernandez-Palacio and Gabriella Cavallo and Alessandro Luzio and Johannes Haataja and Gabriele Giancane and Marco Saccone and Arri Priim{\"a}gi and Pierangelo Metrangolo and Olli Ikkala", year = "2017", month = "3", day = "9", doi = "10.1016/j.chempr.2017.02.003", language = "English", volume = "2", pages = "417--426", journal = "CheM", issn = "2451-9294", publisher = "Elsevier", number = "3", }
@article{5bb68112ba6f445d99be2a33c43487cc, title = "Electromagnetic nonlinearities in a Roebel-cable-based accelerator magnet prototype: Variational approach", abstract = "Superconducting magnets are the most expensive series of components produced in the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN). When developing such magnets beyond state-of-the-art technology, one possible option is to use high-temperature superconductors (HTS) that are capable of tolerating much higher magnetic fields than low-temperature superconductors (LTS), carrying simultaneously high current densities. Significant cost reductions due to decreased prototype construction needs can be achieved by careful modelling of the magnets. Simulations are used, e.g. for designing magnets fulfilling the field quality requirements of the beampipe, and adequate protection by studying the losses occurring during charging and discharging. We model the hysteresis losses and the magnetic field nonlinearity in the beampipe as a function of the magnet's current. These simulations rely on the minimum magnetic energy variation principle, with optimization algorithms provided by the open-source optimization library interior point optimizer. We utilize this methodology to investigate a research and development accelerator magnet prototype made of REBCO Roebel cable. The applicability of this approach, when the magnetic field dependence of the superconductor's critical current density is considered, is discussed. We also scrutinize the influence of the necessary modelling decisions one needs to make with this approach. The results show that different decisions can lead to notably different results, and experiments are required to study the electromagnetic behaviour of such magnets further.", keywords = "AC loss, accelerator magnets, high-temperature superconductors, interior point optimizer, magnetization, minimum magnetic energy variation, nonlinear optimization", author = "J. Ruuskanen and A. Stenvall and V. Lahtinen and E. Pardo", year = "2017", month = "2", day = "1", doi = "10.1088/1361-6668/30/2/024008", language = "English", volume = "30", journal = "Superconductor Science and Technology", issn = "0953-2048", publisher = "IOP Publishing", number = "2", }
@article{05ca7168aea34c418b649b8ebeb3000b, title = "Characterization of the microstructure and corrosion performance of Ce-alloyed Nd-Fe-B magnets", abstract = "Expensive rare-earth elements used in neodymium-iron-boron permanent magnets can be partly replaced by a more abundant cerium without significantly compromising the magnetic properties. In this study, we investigated the effects that cerium addition has on the corrosion resistance of Nd-Fe-B magnets. The cerium-alloyed magnet grade was compared to two Ce-free magnet materials, a standard-grade Nd-Fe-B and a Co-alloyed magnet grade, with respect to microstructure and corrosion behaviour. The microstructure of the magnets was characterized by scanning electron microscopy, with the location of Ce being of primary interest. The magnets were exposed to electrochemical measurements and accelerated corrosion tests. Although the amount of the corrosion-sensitive grain-boundary phase was higher in the Ce-alloyed magnets than in the other two magnet grades, the overall corrosion behaviour was in many ways comparable to that of the Co-alloyed grade magnet, e.g., showing a slight increase in open circuit potential as compared to the standard grade magnet. In accelerated tests, corrosion of the Fe-rich phase was equal to the other magnet grades. Pulverization of the Ce-alloyed magnet was not detected during the accelerated tests, similarly to the Co-alloyed grade.", keywords = "Corrosion, Electrochemical impedance spectroscopy, Rare earth alloys and compounds, Scanning electron microscopy, SEM", author = "Elisa Isotahdon and Elina Huttunen-Saarivirta and Veli Kuokkala", year = "2017", month = "1", doi = "10.1016/j.jallcom.2016.09.058", language = "English", volume = "692", pages = "190--197", journal = "Journal of Alloys and Compounds", issn = "0925-8388", publisher = "Elsevier", }
@article{52bd66bdb95f4d3e87227cd55c518405, title = "Abrasive-Erosive Wear of Thermally Sprayed Coatings from Experimental and Commercial Cr3C2-Based Powders", abstract = "In this paper, high-velocity oxy-fuel sprayed coatings from experimental Cr3C2-Ni powder produced by mechanically activated thermal synthesis and disintegrator milling are compared with coatings from commercial Cr3C2-NiCr powder under room- and elevated-temperature abrasive-erosive wear (AEW) conditions. In a room-temperature AEW test, the coating made from the experimental powder had wear rates that were 1.1-5.3 times higher than the coating from the commercial powder; this difference was the lowest at the highest impact velocity (80 m s−1). Under AEW tests at elevated temperature (300 and 550 °C), the coating made from the experimental powder exhibited wear rates that were 1.2-2.8 times higher in comparison with that made from the commercial powder, but this difference was smaller under an oblique impact angle (30°) and higher temperature conditions. The reasons for the lower resistance against AEW of the coating made from the experimental powder were found to be its lower ability to resist plastic indentation and deformation as well as lower indentation fracture toughness at room temperature, weaker bonding between the matrix and reinforcement and probably lower mechanical properties as well as unfavourable residual stresses at elevated temperatures.", keywords = "abrasive-erosive wear, CrC-based cermet, elevated temperature, mechanically activated thermal synthesis, room temperature, thermal spraying", author = "Heikki Sarjas and Andrei Surzhenkov and Kristjan Juhani and Maksim Antonov and Eron Adoberg and Priit Kulu and Mart Viljus and Rainer Traksmaa and Ville Matikainen and Petri Vuoristo", year = "2017", doi = "10.1007/s11666-017-0638-2", language = "English", volume = "26", pages = "2020–2029", journal = "Journal of Thermal Spray Technology", issn = "1059-9630", publisher = "ASM International", number = "8", }
@article{95eb94acc09648c7a0e33535187bb5ec, title = "Aligned Poly(ε-caprolactone) Nanofibers Guide the Orientation and Migration of Human Pluripotent Stem Cell-Derived Neurons, Astrocytes, and Oligodendrocyte Precursor Cells In Vitro", abstract = "Stem cell transplantations for spinal cord injury (SCI) have been studied extensively for the past decade in order to replace the damaged tissue with human pluripotent stem cell (hPSC)-derived neural cells. Transplanted cells may, however, benefit from supporting and guiding structures or scaffolds in order to remain viable and integrate into the host tissue. Biomaterials can be used as supporting scaffolds, as they mimic the characteristics of the natural cellular environment. In this study, hPSC-derived neurons, astrocytes, and oligodendrocyte precursor cells (OPCs) are cultured on aligned poly(ε-caprolactone) nanofiber platforms, which guide cell orientation to resemble that of spinal cord in vivo. All cell types are shown to efficiently spread over the nanofiber platform and orient according to the fiber alignment. Human neurons and astrocytes require extracellular matrix molecule coating for the nanofibers, but OPCs grow on nanofibers without additional treatment. Furthermore, the nanofiber platform is combined with a 3D hydrogel scaffold with controlled thickness, and nanofiber-mediated orientation of hPSC-derived neurons is also demonstrated in a 3D environment. In this work, clinically relevant materials and substrates for nanofibers, fiber coatings, and hydrogel scaffolds are used and combined with cells suitable for developing functional cell grafts for SCI repair.", keywords = "3D environment, Differentiated neural cell, Human pluripotent stem cell, Nanofiber, Orientation", author = "Anu Hyysalo and Mervi Ristola and Tiina Joki and Mari Honkanen and Minnamari Vippola and Susanna Narkilahti", year = "2017", doi = "10.1002/mabi.201600517", language = "English", volume = "17", journal = "MACROMOLECULAR BIOSCIENCE", issn = "1616-5187", publisher = "Wiley-VCH Verlag", number = "7", }
@article{4a8e70ed2ac7431590619e0763ca9658, title = "HVOF- and HVAF-Sprayed Cr3C2-NiCr Coatings Deposited from Feedstock Powders of Spherical Morphology: Microstructure Formation and High-Stress Abrasive Wear Resistance Up to 800 °C", abstract = "Chromium carbide-based coatings are commonly applied to protect surfaces against wear at high temperatures. This work discusses the influence of feedstock powder and spray torch selection on the microstructure and high-stress abrasion resistance of thermally sprayed Cr3C2-NiCr coatings. Four commercial feedstock powders with spherical morphology and different microstructures were deposited by different high-velocity spray processes, namely third-generation gas- and liquid-fueled HVOF torches and by the latest generation HVAF torch. The microstructures of the coatings were studied in the as-sprayed state and after various heat treatments. The high-stress abrasion resistance of as-sprayed and heat-treated coatings was tested at room temperature and at 800 °C. The study reveals that the selection of the spray torch mainly affects the room temperature abrasion resistance of the as-sprayed coatings, which is due to differences in the embrittlement of the binder phase generated by carbide dissolution. At elevated temperatures, precipitation and growth of secondary carbides yields a fast equalization of the various coatings microstructures and wear properties.", keywords = "abrasion resistance, chromium carbide, feedstock powder, heat treatment, HVAF, HVOF", author = "L. Janka and J. Norpoth and R. Trache and S. Thiele and Berger, {L. M.}", year = "2017", doi = "10.1007/s11666-017-0621-y", language = "English", volume = "26", pages = "1720–1731", journal = "Journal of Thermal Spray Technology", issn = "1059-9630", publisher = "ASM International", number = "7", }
@article{732778d7c4de484eb39648eb479b949f, title = "Load capacity of lubricated bismuth bronze bimetal bearing under elliptical sliding motion", abstract = "Leaded tin bronze alloys are widely used in heavy machinery bearings operating in boundary and mixed lubrication regions due to the excellent dry lubrication properties of lead. However, restrictions on the use of lead have created an increasing demand for lead-free or low-lead bearing materials. In the present study, suitability of a novel bismuth bronze bimetal material for possible substitution of leaded tin bronze was studied with a special thrust bearing test device, which simulates the contact conditions in the main thrust bearing of mineral crushers. The oil-lubricated test bearings have a flat-on-flat type contact with oil grooves and a constant eccentric motion against a case hardened steel counter plate under a periodically increased axial pressure. The test was continued until a sudden rise in friction, which indicates bearing failure and risk of an imminent seizure. The bismuth bronze showed a load capacity of the same level with the reference material, continuously cast CuSn10Pb10. Characterization by electron microscopy showed that the dry-lubricating bismuth precipitations had a fine grain size and an even distribution, which explains the good load carrying capacity. It was concluded that the bismuth bronze has potential for substituting the leaded tin bronzes in the studied operating conditions.", keywords = "Bearings, Bimetals, Lead substitution, Non-ferrous metals, Solid lubricants", author = "Oksanen, {V. T.} and Lehtovaara, {A. J.} and Kallio, {M. H.}", year = "2017", doi = "10.1016/j.wear.2017.05.001", language = "English", volume = "388-389", pages = "72--80", journal = "Wear", issn = "0043-1648", publisher = "Elsevier", }
@article{135c5181a8e04b2297b12ca9867355ea, title = "Non-destructive and wireless monitoring of biodegradable polymers", abstract = "A method for monitoring changes in biodegradable polymers during hydrolysis is proposed. This wireless and non-destructive method is based on inductively coupled passive resonance sensors embedded in the polymer shell. In this study, we prepared specimens using two poly(lactide-co-glycolide) copolymers possessing different degradation profiles. The copolymer embedded sensors were immersed in buffer solution and their resonance features were compared with periodically performed conventional polymer characterization methods. A clear difference was noticed in the wirelessly measured signals between the two tested copolymer materials. Also the reference methods showed clear differences between the degradation profiles of the copolymers. The wirelessly measured signals are likely to correlate to the structural changes in the materials during the hydrolysis. In the future, this technique could be used in the laboratory to provide easy-to-access in situ information about the polymers. Even the state of biodegradable polymer implants could be wirelessly monitored.", keywords = "Biodegradable polymers, Passive resonance sensor, Poly(lactide-co-glycolide), Telemetry, Wireless monitoring", author = "Timo Salpavaara and Aleksi H{\"a}nninen and Anni Antniemi and Jukka Lekkala and Minna Kellom{\"a}ki", year = "2017", doi = "10.1016/j.snb.2017.05.116", language = "English", volume = "251", pages = "1018--1025", journal = "Sensors and Actuators B: Chemical", issn = "0925-4005", publisher = "Elsevier Science", }
@article{94ca2515597b4e81b92c96568f96e69c, title = "Sliding wear behaviour of HVOF and HVAF sprayed Cr3C2-based coatings", abstract = "Thermally sprayed tungsten carbide (WC) and chromium carbide (Cr3C2) based hard metal coatings are commonly applied on component surfaces as corrosion and wear resistant layers. Typically, WC-Co/Ni with optional Cr addition and Cr3C2-25NiCr powders are sprayed with high velocity oxy-fuel (HVOF) or high velocity air-fuel (HVAF) processes. Due to the poor oxidation resistance of the WC particles, Cr3C2-25NiCr composition is typically selected for high temperature environments, up to 800-900°C. In this study, two distinct Cr3C2-based compositions of Cr3C2-50NiCrMoNb and Cr3C2-37WC-18NiCoCr were selected as interesting alternatives to conventional Cr3C2-25NiCr. Sliding wear behavior of the coatings sprayed with HVOF and HVAF processes were tested with a ball-on-disk configuration against an Al2O3 ball at room temperature and at 700°C. It was found that both alternative materials had comparable coefficients of friction with the Cr3C2-25NiCr coatings. The Cr3C2-37WC-18NiCoCr coatings provided improved wear resistance at room temperature conditions, but at 700°C the wear rate was increased to the level of the Cr3C2-50NiCrMoNb coatings. Cr3C2-25NiCr coatings experienced the lowest wear rates at elevated temperatures, which was even lower than at room temperature.", keywords = "CrC, HVAF, HVOF, Sliding wear, Thermal spray coatings", author = "V. Matikainen and G. Bolelli and H. Koivuluoto and P. Sassatelli and L. Lusvarghi and P. Vuoristo", year = "2017", doi = "10.1016/j.wear.2017.04.001", language = "English", volume = "388-389", pages = "57--71", journal = "Wear", issn = "0043-1648", publisher = "Elsevier", }
@article{452cbd8269b14634a2d998559a75f3e0, title = "The 5th international workshop on numerical modelling of high temperature superconductors", author = "Antonio Morandi and Ainslie, {Mark D.} and Francesco Grilli and Antti Stenvall", year = "2017", doi = "10.1088/1361-6668/aa7676", language = "English", volume = "30", journal = "Superconductor Science and Technology", issn = "0953-2048", publisher = "IOP Publishing", number = "8", }
@article{b9ea51c4baa6425d9184416cc5459e75, title = "Two cations, two mechanisms: Interactions of sodium and calcium with zwitterionic lipid membranes", abstract = "Adsorption of metal cations onto a cellular membrane changes its properties, such as interactions with charged moieties or the propensity for membrane fusion. It is, however, unclear whether cells can regulate ion adsorption and the related functions via locally adjusting their membrane composition. We employed fluorescence techniques and computer simulations to determine how the presence of cholesterol - a key molecule inducing membrane heterogeneity - affects the adsorption of sodium and calcium onto zwitterionic phosphatidylcholine bilayers. We found that the transient adsorption of sodium is dependent on the number of phosphatidylcholine head groups, while the strong surface binding of calcium is determined by the available surface area of the membrane. Cholesterol thus does not affect sodium adsorption and only plays an indirect role in modulating the adsorption of calcium by increasing the total surface area of the membrane. These observations also indicate how lateral lipid heterogeneity can regulate various ion-induced processes including adsorption of peripheral proteins, nanoparticles, and other molecules onto membranes.", author = "Matti Javanainen and Ad{\'e}la Melcrov{\'a} and Aniket Magarkar and Piotr Jurkiewicz and Martin Hof and Pavel Jungwirth and Hector Martinez-Seara", year = "2017", doi = "10.1039/c7cc02208e", language = "English", volume = "53", pages = "5380--5383", journal = "Chemical Communications", issn = "1359-7345", publisher = "ROYAL SOC CHEMISTRY", number = "39", }
@article{ebf6e4cddd134b83bb0eced732828c51, title = "Optimization of HVOF Cr3C2-NiCr coating for increased fatigue performance", abstract = "Thermally sprayed coatings are strong candidates to be used for replacement of hard chromium – process which is regarded as an environmental risk – in many sliding surfaces for engineering applications such as hydraulic cylinders and aircraft landing gears. Recent advance in thermal spraying technology, based on the increase of the spray particle velocity, has led to improved coating quality. This study focuses on the fatigue performance of structural steel coated with Cr3C2[Formula presented] coating. Coating has been produced by using high kinetic HVOF thermal spray process. First, the coating was optimized for fatigue purposes by studying the residual stress generation. The optimized coating was selected for deposition of axial fatigue tests specimens, whose fatigue performance was compared to the uncoated steel specimens having different surface treatments (turning, polishing, and shot blasting) relevant for the target applications. The results showed that by using a high kinetic energy coating, the fatigue performance of Cr3C2[Formula presented] coated structural steel was clearly improved compared to uncoated steel of similar surface quality. Increased fatigue resistance of the coated material was attributed to the substantial compressive residual stresses that hindered crack initiation and that was caused by the high velocity spray particles during the coating process.", keywords = "CrC[Formula presented] coating, Fatigue performance, HVOF thermal spray, Residual stress, S-N curve, Wear resistance", author = "T. Varis and T. Suhonen and O. Calonius and J. Čuban and M. Pietola", year = "2016", month = "11", day = "15", doi = "10.1016/j.surfcoat.2016.08.012", language = "English", volume = "305", pages = "123--131", journal = "Surface & Coatings Technology", issn = "0257-8972", publisher = "Elsevier", }
@article{3e7fc9937d9a4ecd8173d13e350f533e, title = "Improvement of actuation performance of dielectric elastomers by barium titanate and carbon black fillers", abstract = "Dielectric elastomers are promising materials for actuators resembling human muscle. Among elastomers, acrylic rubbers (ACM) have shown good actuation performance but its use is limited by the high operating voltages required. The present work demonstrates that simultaneous incorporation of nanostructured carbon black and dielectric fillers offers an increase in a dielectric permittivity and a suitable modulus of the elastomers matrix, enabling an improved electro-mechanical actuation performance at low voltages. By the use of reinforcing carbon black and barium titanate in an acrylic elastomer matrix a sixfold increase in the dielectric permittivity was realized. A fine tuning of the actuation stress and, consequently, actuation strain can be done by a judicial selection of the different filler concentrations in the soft rubber matrix. Finally, a synergistic effect of the fillers was observed in the improved actuation performance of the developed materials. This work may pave the way to design dielectric elastomers for actuator fabrication.", keywords = "actuators, dielectric properties, elastomers", author = "Minna Poikelisp{\"a}{\"a} and Alexandra Shakun and Amit Das and Jyrki Vuorinen", year = "2016", month = "11", day = "10", doi = "10.1002/app.44116", language = "English", volume = "133", journal = "Journal of Applied Polymer Science", issn = "0021-8995", publisher = "Wiley", number = "42", }
@article{413b8771f0474346930a009594e23dc9, title = "Erosion–corrosion resistance of various stainless steel grades in high-temperature sulfuric acid solution", abstract = "Two austenitic stainless steel grades, 316L and 904L, and three duplex stainless steel grades, LDX 2101, 2205, and 2507, were erosion–corrosion tested as impeller blade materials for hydrometallurgical applications. Samples were attached to the pressure and suction sides of an impeller and were tested in 50 g/l H2SO4 and 0.5 g/l Fe2(SO4)3 for 72 h at 80°C and 95 °C in a small-scale reactor using quartz sand slurry. The results showed that under lower erosion intensity the ranking of the grades was similar to that in pure erosion. Under higher erosion intensity the ranking of the grades changed completely: lean alloys LDX 2101 and 316L suffered from the highest mass losses followed by 2205, 2507, and 904L. To clarify this behavior, the ability of the grades to repassivate was investigated with scratch tests. It was found that the ranking could be explained by the repassivation rates. The only exception was that 2507 showed a similar repassivation rate to 904L but its erosion–corrosion mass loss under higher erosion intensity was larger. One contributing factor to this was found to be the selective dissolution of the austenite phase of all the tested duplex grades. The prerequisites for the galvanic coupling between the phases that was responsible for the selective dissolution are discussed.", keywords = "Erosion–corrosion, Slurry, Stainless steels, Sulfuric acid, Wear", author = "M. Lindgren and S. Siljander and R. Suihkonen and P. Pohjanne and J. Vuorinen", note = "EXT={"}Lindgren, M.{"}", year = "2016", month = "10", day = "15", doi = "10.1016/j.wear.2016.06.007", language = "English", volume = "364-365", pages = "10--21", journal = "Wear", issn = "0043-1648", publisher = "Elsevier", }
@article{837cbf3d01a748bd8b6c6bd747c0c940, title = "Photocatalytic and antibacterial properties of ZnO films with different surface topographies on stainless steel substrate", abstract = "Zinc oxide films with three types of topographies: needle-like and hexagonal rods and flakes, were prepared by hydrothermal synthesis on stainless steel substrates to investigate their photocatalytic and antibacterial properties. The photocatalytic activity was measured with a methylene blue (MB) discoloration test, whereas a method using bioluminescent whole cell bacterial biosensors enabling the constant monitoring of the amount of living cells on the surfaces was used here to study the antibacterial properties. The results showed that photocatalytic activity was clearly influenced by the surface area, which is in turn dependent on the topography. Moreover, it was found that all the examined films decreased notably the amount of Staphylococcus aureus and Escherichia coli on the surfaces. Despite significant differences in the surface areas of the studied samples that led to different zinc dissolution rate in aqueous environment, no notable differences in antibacterial activity between the films with different morphologies could be detected. These results are presented and discussed in this paper.", keywords = "Antibacterial, Biosensor cell, Hydrothermal synthesis, Photocatalytic activity, Zinc oxide", author = "Saara Heinonen and Matti Kannisto and Juha-Pekka Nikkanen and Elina Huttunen-Saarivirta and Matti Karp and Erkki Lev{\"a}nen", year = "2016", month = "10", day = "1", doi = "10.1016/j.tsf.2016.10.002", language = "English", volume = "616", pages = "842--849", journal = "Thin Solid Films", issn = "0040-6090", publisher = "Elsevier", }
@article{875c97e5e62d4f498f65077c2a012333, title = "Polyarginine Interacts More Strongly and Cooperatively than Polylysine with Phospholipid Bilayers", abstract = "The interactions of two highly positively charged short peptide sequences with negatively charged lipid bilayers were explored by fluorescence binding assays and all-atom molecular dynamics simulations. The bilayers consisted of mixtures of phosphatidylglycerol (PG) and phosphatidylcholine (PC) lipids as well as a fluorescence probe that was sensitive to the interfacial potential. The first peptide contained nine arginine repeats (Arg9), and the second one had nine lysine repeats (Lys9). The experimentally determined apparent dissociation constants and Hill cooperativity coefficients demonstrated that the Arg9 peptides exhibited weakly anticooperative binding behavior at the bilayer interface at lower PG concentrations, but this anticooperative effect vanished once the bilayers contained at least 20 mol {\%} PG. By contrast, Lys9 peptides showed strongly anticooperative binding behavior at all PG concentrations, and the dissociation constants with Lys9 were approximately 2 orders of magnitude higher than with Arg9. Moreover, only arginine-rich peptides could bind to the phospholipid bilayers containing just PC lipids. These results along with the corresponding molecular dynamics simulations suggested two important distinctions between the behavior of Arg9 and Lys9 that led to these striking differences in binding and cooperativity. First, the interactions of the guanidinium moieties on the Arg side chains with the phospholipid head groups were stronger than for the amino group. This helped facilitate stronger Arg9 binding at all PG concentrations that were tested. However, at PG concentrations of 20 mol {\%} or greater, the Arg9 peptides came into sufficiently close proximity with each other so that favorable like-charge pairing between the guanidinium moieties could just offset the long-range electrostatic repulsions. This led to Arg9 aggregation at the bilayer surface. By contrast, Lys9 molecules experienced electrostatic repulsion from each other at all PG concentrations. These insights may help explain the propensity for cell penetrating peptides containing arginine to more effectively cross cell membranes in comparison with lysine-rich peptides.", author = "Robison, {Aaron D.} and Simou Sun and Poyton, {Matthew F.} and Johnson, {Gregory A.} and Pellois, {Jean Philippe} and Pavel Jungwirth and Mario Vazdar and Cremer, {Paul S.}", year = "2016", month = "9", day = "8", doi = "10.1021/acs.jpcb.6b05604", language = "English", volume = "120", pages = "9287--9296", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "35", }
@article{f3a11e74f5874f6588d61793da22860a, title = "Barkhausen noise response of three different welded duplex stainless steels", abstract = "An investigation was made into the Barkhausen noise responses of three duplex grades: a lean alloy LDX 2101, a conventional duplex 2205 and a super duplex 2507, in welded conditions. The aim was to study the influence of alloy chemistry and microstructure on the Barkhausen noise response. In addition, the residual stresses of the grades were measured by X-ray diffraction and the microstructure and hardness of the base materials and welds were determined. It was observed that the Barkhausen noise responses in the rolling direction and in the transverse direction were governed by the phase morphology of the materials. Only the root mean square of the Barkhausen noise burst seemed to be additionally dependent on the alloy chemistry through the hardness of the materials. Furthermore, the relationships between various characteristics of the Barkhausen noise burst measured in the rolling direction and the transverse direction and microstructural features are discussed.", keywords = "Barkhausen, Stainless steel, Welds", author = "M. Lindgren and S. Santa-aho and M. Vippola", year = "2016", month = "9", day = "1", doi = "10.1784/insi.2016.58.9.480", language = "English", volume = "58", pages = "480--486", journal = "Insight", issn = "1354-2575", publisher = "British Institute of Non-destructive Testing", number = "9", }
@article{84d8b671359c4256923f36eb13e42af3, title = "Detergent impurity effect on recycled HDPE: Properties after repetitive processing", abstract = "High density polyethylene (rHDPE) is extruded 1 to 8 times, with and without detergent, to simulate the effects of impurities on the material and on the artificial ageing process. The mechanical properties, thermal stability, rheology, Fourier transform infrared spectroscopy (FTIR), and volatile organic compound (VOC) emissions are measured. According to the results, ageing of rHDPE increases tensile strength, reduces elongation, and enhances side chain branching of the material and thus causes rheological changes. The addition of detergent reduces changes in mechanical properties and rheological behavior but accelerates thermal degradation. VOC and FTIR measurements of the samples with detergent addition show generation of harmful 1,4-dioxane. The amount of total emission, as well as emissions of important perfumes limonene and 1R-α-pinene, decreases during multiple extrusion cycles. Heating of the plastics is found to be a major factor in the VOC emission reduction. Impurities have a notable effect on the artificial ageing results.", keywords = "Ageing, Degradation, Polyolefins, Recycling", author = "Ville Myll{\"a}ri and Samuel Hartikainen and Valeria Poliakova and Reetta Anderson and Ilari J{\"o}nkk{\"a}ri and Pertti Pasanen and Mirja Andersson and Jyrki Vuorinen", year = "2016", month = "8", day = "15", doi = "10.1002/app.43766", language = "English", volume = "133", journal = "Journal of Applied Polymer Science", issn = "0021-8995", publisher = "Wiley", number = "31", }
@article{fd4e3e222ffe48caa7995a083f2d03e7, title = "Reinforced chloroprene rubber by in situ generated silica particles: Evidence of bound rubber on the silica surface", abstract = "Nano silica is generated in situ inside the uncrosslinked chloroprene rubber (CR) by the sol-gel reaction of tetraethoxysilane (TEOS). This results in appreciable improvement in mechanical properties of the CR composites at relatively low filler content. Furthermore, exploitation of reactive organosilanes, γ-aminopropyltrimethoxysilane (γ-APS) in particular, in the silica synthesis process facilitates growing of spherical silica particles with a size distribution in the range of 20-50 nm. The silica particles are found to be uniformly dispersed and they do not suffer from filler-filler interaction. Additionally, it is observed that the silica particles are coated by silane and rubber chains together which are popularly known as bound rubber. The existence of the bound rubber on silica surface has been supported by the detailed investigations with transmission electron microscopy (TEM), energy filtered transmission electron microscopy (EFTEM) and energy dispersive X-ray spectroscopy (EDAX). The interaction between rubber and silica, via bi-functionality of the γ-APS, has been explored by detailed FTIR studies.", keywords = "bound rubber, in situ silica and silane treatment, transmission electron microscopy", author = "Kapgate, {Bharat P.} and Chayan Das and Amit Das and Debdipta Basu and Sven Wiessner and Uta Reuter and Gert Heinrich", year = "2016", month = "8", day = "10", doi = "10.1002/app.43717", language = "English", volume = "133", journal = "Journal of Applied Polymer Science", issn = "0021-8995", publisher = "Wiley", number = "30", }
@article{ec7dcc1ed5b941a2a159179f19956468, title = "Novel oxyfluorophosphate glasses and glass-ceramics", abstract = "Effect of CaF2 addition at the expense of CaO on the thermal, physical, optical and structural properties of glasses in the NaPO3-CaO system was studied. The glasses were prepared by the conventional melt quenching method. For each glass, the thermal properties were studied by differential thermal analysis (DTA) and the optical properties by UV-Vis-NIR spectroscopy. The changes in the glass structure induced by the progressive replacement of CaO by CaF2 were investigated using IR and Raman spectroscopies. The glasses were heat treated at 20 °C above their respective glass transition temperature for 17 h to form nuclei and then at their peak crystallization temperature for 1 h to grow the nuclei into crystals. An increase in the CaF2 content increased the polymerization of the phosphate network leading to shift of the band gap to lower wavelength and reduced the crystallization tendency of the glasses. At least two crystalline phases precipitated in all the investigated glasses, the composition of which depended on the CaF2 content. Finally, bulk crystallization was suspected to occur in the oxyfluorophosphate glasses.", keywords = "Crystallization, Fluorophosphate glasses and glass-ceramics, Raman and IR spectroscopies, XRD", author = "S. Cui and J. Massera and M. Lastusaari and L. Hupa and L. Petit", year = "2016", month = "8", day = "1", doi = "10.1016/j.jnoncrysol.2016.05.005", language = "English", volume = "445-446", pages = "40--44", journal = "Journal of Non-Crystalline Solids", issn = "0022-3093", publisher = "Elsevier", }
@article{61d323147302496baff8d04183c70c70, title = "The red, purple and blue modifications of polymeric unsymmetrical hydroxyalkadiynyl-N-arylcarbamate derivatives in Langmuir-Schaefer films", abstract = "Solid topochemical photopolymerization (STP) of Langmuir-Schaefer films of a new class of unsymmetrical diynes, containing N-arylcarbamate groups in the hydrophobic part and hydroxymethylene groups in the hydrophilic part of the molecules was examined. In addition, the monomeric Langmuir monolayer formation was studied by Brewster angle microscopy and the surface morphology of monomer and polymer films on solid substrates were studied by scanning electron microscopy and atomic force microscopy. Three phases of polydiacetylene (PDA) (red, purple and blue) were observed after UV-light polymerization of above-mentioned films of alcohol diacetylene (DA) derivatives. The substitution of MeO group in the aryl ring substituent by hydrogen atom and the variation of the methylene group number in the hydrophobic part from 5 to 6 changed significantly the result of STP: instead of blue phase PDA observed for diynes with MeO group, the red phase PDA was observed for DA with H-atom from the very beginning of diyne film UV irradiation. For two other diynilic N-arylcarbamates of identical chemical structures except of the substituents in the aryl ring of hydrophobic parts of the molecules, no changes in the efficiency of polymerization or the position and shape of absorption bands were observed. This indicated the formation of the purple phase PDA. For these molecules, the number of methylene groups in hydrophobic and hydrophilic parts of the molecules was 9 and 2, respectively.", keywords = "Langmuir monolayer, Langmuir-Schaefer film, Polydiacetylenes with urethane group, Solid topochemical photopolymerization", author = "Alexander Alekseev and Petri Ihalainen and Artem Ivanov and Ivan Domnin and Vera Klechkovskaya and Anton Orekhov and Helge Lemmetyinen and Elina Vuorimaa-Laukkanen and Jouko Peltonen and Sergey Vyaz'min", note = "EXT={"}Alekseev, Alexander{"}", year = "2016", month = "8", day = "1", doi = "10.1016/j.tsf.2016.06.044", language = "English", volume = "612", pages = "463--471", journal = "Thin Solid Films", issn = "0040-6090", publisher = "Elsevier", }
@article{5bb1f2672e844a73a7a0cf74e3c91ef2, title = "Erosion wear of vinylester matrix composites in aqueous and acidic environments at elevated temperatures", abstract = "Slurry erosion wear performance of glass fibre reinforced vinylester composite (FRP) has been studied using a pilot-scale erosion test apparatus. Tests were conducted at elevated temperatures in aqueous and acidic environments. When using fine quartz as an abrasive material, FRP showed higher mass losses in the aqueous environment than in the acidic conditions, especially at higher temperatures. In this case, the FRP degradation was governed by the penetration of the used medium into the FRP structure. According to the absorption studies, the weight gain of the laminate was more pronounced in the water immersion compared to the acidic solution, which can be a prediction of an increased degradation rate and explain the higher wear in the aqueous medium. When the abrasive material was changed from fine to coarse quartz, the removal of the shielding matrix phase was extensive and a direct route for the acidic solution to the fibres was created causing more severe damage. This was also shown in scanning electron microscopy (SEM) studies, where the samples tested in the acidic solution showed extensive fibre flattening along the erosion flux. By increasing the test temperature close to the boiling point of the medium, an increase in the FRP wear could be seen. The increase in the rotation speed, on the other hand, did not automatically mean higher mass losses. This shows that the wear environment in the present test device is highly complicated with several interrelated parameters affecting the results.", keywords = "Erosion testing, Erosion-corrosion, Polymer-matrix composite, Slurry erosion", author = "Reija Suihkonen and Mari Lindgren and Sanna Siljander and Essi Sarlin and Jyrki Vuorinen", note = "EXT={"}Lindgren, Mari{"}", year = "2016", month = "7", day = "15", doi = "10.1016/j.wear.2016.03.026", language = "English", volume = "358-359", pages = "7--16", journal = "Wear", issn = "0043-1648", publisher = "Elsevier", }
@article{09b74027674041738a5cfce42823488b, title = "Sliding and abrasive wear behaviour of HVOF- and HVAF-sprayed Cr3C2-NiCr hardmetal coatings", abstract = "This paper provides a comprehensive characterisation of HVOF- and HVAF-sprayed Cr3C2-25 wt.{\%} NiCr hardmetal coatings. One commercial powder composition with two different particle size distributions was processed using five HVOF and HVAF thermal spray systems. All coatings contain less Cr3C2 than the feedstock powder, possibly due to the rebound of some Cr3C2-rich particles during high-velocity impact onto the substrate. Dry sand-rubber wheel abrasive wear testing causes both grooving and pull-out of splat fragments. Mass losses depend on inter- and intra-lamellar cohesion, being higher (≥70 mg after a wear distance of 5904 m) for the coatings deposited with the coarser feedstock powder or with one type of HVAF torch. Sliding wear at room temperature against alumina involves shallower abrasive grooving, small-scale delamination and carbide pull-outs, and it is controlled by intra-lamellar cohesion. The coatings obtained from the fine feedstock powder exhibit the lowest wear rates (≈5×10-6 mm3/(Nm)). At 400 °C, abrasive grooving dominates the sliding wear behaviour; wear rates increase by one order of magnitude but friction coefficients decrease from ≈0.7 to ≈0.5. The thermal expansion coefficient of the coatings (11.08×10-6 °C-1 in the 30-400 °C range) is sufficiently close to that of the steel substrate (14.23×10-6 °C-1) to avoid macro-cracking.", keywords = "Cermets, High temperature, Indentation, Sliding wear, Thermal spray coatings, Three-body abrasion", author = "G. Bolelli and Berger, {L. M.} and T. B{\"o}rner and H. Koivuluoto and V. Matikainen and L. Lusvarghi and C. Lyphout and N. Markocsan and P. Nyl{\'e}n and P. Sassatelli and R. Trache and P. Vuoristo", year = "2016", month = "7", day = "15", doi = "10.1016/j.wear.2016.03.034", language = "English", volume = "358-359", pages = "32--50", journal = "Wear", issn = "0043-1648", publisher = "Elsevier", }
@article{c049a9223f50459bb0e2abf0345484c5, title = "Characterization of High-Velocity Single Particle Impacts on Plasma-Sprayed Ceramic Coatings", abstract = "High-velocity impact wear can have a significant effect on the lifetime of thermally sprayed coatings in multiple applications, e.g., in the process and paper industries. Plasma-sprayed oxide coatings, such as Cr2O3- and TiO2-based coatings, are often used in these industries in wear and corrosion applications. An experimental impact study was performed on thermally sprayed ceramic coatings using the High-Velocity Particle Impactor (HVPI) at oblique angles to investigate the damage, failure, and deformation of the coated structures. The impact site was characterized by profilometry, optical microscopy, and scanning electron microscopy (SEM). Furthermore, the connection between the microstructural details and impact behavior was studied in order to reveal the damage and failure characteristics at a more comprehensive level. Differences in the fracture behavior were found between the thermally sprayed Cr2O3 and TiO2 coatings, and a concept of critical impact energy is presented here. The superior cohesion of the TiO2 coating inhibited interlamellar cracking while the Cr2O3 coating suffered greater damage at high impact energies. The HVPI experiment has proven to be able to produce valuable information about the deformation behavior of coatings under high strain rates and could be utilized further in the development of wear-resistant coatings.", keywords = "electron microscopy, fracture, impact wear, thermal spray coatings, wear testing", author = "Jarkko Kiilakoski and Matti Lindroos and Marian Apostol and Heli Koivuluoto and Veli-Tapani Kuokkala and Petri Vuoristo", year = "2016", month = "6", day = "24", doi = "10.1007/s11666-016-0428-2", language = "English", volume = "25", pages = "1127--1137", journal = "Journal of Thermal Spray Technology", issn = "1059-9630", publisher = "ASM International", }
@article{3a88c9cab41344149dcc8c5908c2d57b, title = "Structurally Controlled Dynamics in Azobenzene-Based Supramolecular Self-Assemblies in Solid State", abstract = "Light-responsive supramolecular self-assemblies exhibit interplay between order and dynamics of the self-assembling motifs, through which the thermal isomerization rate of azobenzene chromophores can be tuned by orders of magnitude. By using supramolecular complexes of 4-(4-alkylphenylazo)phenols hydrogen-bonded to poly(4-vinylpyridine) as model systems, we demonstrate that the thermal isomerization rate of the hydroxyazobenzene derivatives increases 5700-fold when the material undergoes a transformation from a disordered, low-azobenzene-concentration state to a high-concentration state exhibiting lamellar, smectic-like self-assembly. Drastically smaller thermal isomerization rates are observed in disordered structures. This allows us to attribute the change to a combination of increased number density of the hydroxyazobenzenes inducing plasticization, and cooperativity created by the chromophore-chromophore interactions through self-assembled molecular order and alignment. Our results pinpoint the importance of molecular self-assembly and intermolecular interactions in modifying the dynamics in supramolecular complexes in a controlled manner. We foresee this to be important in light-controlled dynamic materials.", author = "Mikko Poutanen and Olli Ikkala and Arri Priim{\"a}gi", year = "2016", month = "6", day = "14", doi = "10.1021/acs.macromol.6b00562", language = "English", volume = "49", pages = "4095--4101", journal = "Macromolecules", issn = "0024-9297", publisher = "American Chemical Society", number = "11", }
@article{7d823f919b7d4d589d553ac424be31aa, title = "Effect of incorporation of CdS NPs on performance of PTB7: PCBM organic solar cells", abstract = "It has been well known that incorporation of nano-heterostructures of various metals, semiconductors and dielectric materials in the active layer of organic solar cells (OSCs) helps in improving power conversion efficiency (PCE). In the present study, we demonstrated microwave synthesis of CdS nanoparticles (NPs) for their application in one of most efficient OSCs consisting of poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl] [3-fluoro-2-[(2-ethylhexyl)carbonyl] thieno[3,4-b]thiophenediyl]] (PTB7): [6,6]-phenyl C71-butyric acid methyl ester (PCBM) photoactive blend. This is crucial to fully explore the promising features of low cost and scalability in organic-inorganic hybrid solar cells. Synthesized CdS NPs are slightly elongated and highly crystalline with their absorption lies in the visible region as confirmed by High resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), UV-Vis absorption spectroscopy studies. Our experimental results for the devices in an inverted geometry having a structure ITO/ZnO/PTB7: CdS: PCBM/MoO3/Ag has shown increase in Jsc and PCE by nearly 10{\%}. However, it was observed that this increase is only when NPs were added in the low concentration in active layer. UV-Vis absorption spectroscopy, Photoluminescence (PL) and atomic force microscopy (AFM) studies were carried out in order understand the device performance.", keywords = "CdS nanoparticles, Microwave synthesis, Organic solar cells, PCBM, PL quenching, PTB7", author = "Ramakant Sharma and Sagar Bhalerao and Dipti Gupta", year = "2016", month = "6", day = "1", doi = "10.1016/j.orgel.2016.03.030", language = "English", volume = "33", pages = "274--280", journal = "Organic Electronics", issn = "1566-1199", publisher = "Elsevier Science B.V.", }
@article{b72c51dfad8044f2b483c365561625c6, title = "Microstructure and Sliding Wear Behavior of Fe-Based Coatings Manufactured with HVOF and HVAF Thermal Spray Processes", abstract = "The microstructure and micromechanical behavior of thermally sprayed Fe-based coatings manufactured with high-velocity oxygen fuel (HVOF) and high-velocity air fuel (HVAF) processes were investigated. Fe-Cr-Ni-Si-B-C and Fe-Cr-Ni-Mo-Si-B-C powders were used as the feedstock materials. The coatings showed a highly dense microstructure with near-zero oxidation. The microstructure of the feedstock powders was better retained when sprayed with HVAF process. Differential scanning calorimetry revealed two small exothermic peaks at about 600 °C for the HVOF-sprayed coatings, without any increase in weight in thermogravimetric analysis. It suggested the re-precipitation of carbides that were dissolved during spraying due to the higher particle temperature reported by spray diagnostics system during the HVOF process (≈1800 °C) compared to the HVAF one (≈1400 °C). Micro- and nano-indentations helped to show the difference in inter-lamellar cohesive strength and, in turn, in the particle deposition mechanism. Coatings sprayed with Fe-Cr-Ni-Mo-Si-B-C composition possessed higher sliding wear resistance than that of Fe-Cr-Ni-Si-B-C due to higher nano-hardness. More specifically, HVOF-sprayed Fe-Cr-Ni-Mo-Si-B-C coating showed the largest intra-lamellar hardness, the largest elasticity, and high quality of particle interfaces which resulted in lower sliding wear rate.", keywords = "iron alloys, protective coatings, wear resistant coatings", author = "A. Milanti and V. Matikainen and G. Bolelli and H. Koivuluoto and L. Lusvarghi and P. Vuoristo", year = "2016", month = "6", doi = "10.1007/s11666-016-0410-z", language = "English", volume = "25", pages = "1040–1055", journal = "Journal of Thermal Spray Technology", issn = "1059-9630", publisher = "ASM International", number = "5", }
@article{aeee130eae6047f5bb649b99ba591bca, title = "Influence of heat treatment on the abrasive wear resistance of a Cr3C2NiCr coating deposited by an ethene-fuelled HVOF spray process", abstract = "This work reveals the influence of heat treatments on the microstructure, mechanical properties and abrasive wear behaviour of a Cr3C2NiCr coating deposited by an ethene-fuelled high-velocity oxygen-fuel spray process using an agglomerated-and-sintered feedstock powder. The wear resistance of an as-sprayed and heat treated (8 h at 800 °C) coating was evaluated in low- and high-stress abrasion regimes, the latter in a temperature range up to 800 °C. Precipitation of secondary carbides from the supersaturated as-sprayed binder matrix is at the core of the observed changes in the coatings wear resistance upon heat treating. This aging process renders the binder matrix softer and more ductile, as was probed by means of nanoindentation, and thereby improves its resistance against micro-cracking which is identified as an important wear mechanism in high-stress abrasion conditions.", keywords = "Abrasion, CrC, Heat treatment, HVOF, Mechanical properties", author = "Leo Janka and Jonas Norpoth and Richard Trache and Berger, {Lutz Michael}", year = "2016", month = "4", day = "15", doi = "10.1016/j.surfcoat.2016.02.066", language = "English", volume = "291", pages = "444--451", journal = "Surface & Coatings Technology", issn = "0257-8972", publisher = "Elsevier", }
@article{1480d059aa434b78894517c2b543861f, title = "Thermal, structural and optical properties of Er3+ doped phosphate glasses containing silver nanoparticles", abstract = "The melt-quenching method is employed to prepare the amorphous phosphate glasses containing silver nanoparticles (Ag NPs). The structural characteristics of phosphate glasses were investigated by X-ray diffraction, thermal analysis, transmission electron microscopy, UV-Vis spectroscopy, Raman, and infrared spectroscopy. The transmission electron microscopic images confirm the presence of spherical silver NPs having an average diameter in the range of 20-40 nm. The EDX analysis spectrum shows the presence of Ag element. Important structural changes induced by the Ag2CO3 addition to the phosphate glass, Raman- and IR-spectroscopic studies were carried out in order to correlate the variations in the glass properties with variations of the glass structure. The surface plasmon resonance (SPR) peak of silver nanoparticles embedded in Er3 + doped phosphate glass is evidenced at ∼403 nm. From the absorption spectra, the optical band gap is found to decrease with the increase of Ag NPs' concentration. All the obtained results in the present study were reported and discussed in detail.", keywords = "FTIR and Raman spectra, Phosphate glasses, Silver nanoparticles (Ag NPs), Thermal stability", author = "I. Soltani and S. Hraiech and K. Horchani-Naifer and J. Massera and L. Petit and M. F{\'e}rid", note = "EXT={"}Petit, L.{"}", year = "2016", month = "4", day = "15", doi = "10.1016/j.jnoncrysol.2015.12.022", language = "English", volume = "438", pages = "67--73", journal = "Journal of Non-Crystalline Solids", issn = "0022-3093", publisher = "Elsevier", }
@article{cc848d0ff10540afa659a8841a00155e, title = "Chemical synthesis of WC-Co from water-soluble precursors: The effect of carbon and cobalt additions to WC synthesis", abstract = "The chemical synthesis of WC-Co from water-soluble precursors and the effect of carbon content and cobalt addition were studied. Ammonium metatungstate AMT as tungsten source, glycine as a carbon source and cobalt acetate Co(C2H3O2)2 as a cobalt source was dissolved in water and spray-dried, and thermal synthesis in Ar atmosphere was performed. In order to understand the effects of carbon content and cobalt addition on synthesis steps, and the chemical and phase structure, thermogravimetry (TGA) with Differential Scanning Calorimetry (DCS) and mass spectrometry was used together with X-ray diffractometry and chemical analysis. The results reveal that carbon content mainly affected reduction temperatures and cobalt addition to reaction route and solid state synthesis temperature. This presented manufacturing route with water-soluble raw materials was a potential way of preparing nanostructural WC-Co composition with the correct phase structure and chemical composition.", keywords = "Nano-sized WC-Co synthesis, Spray drying, Water soluble precursors", author = "Ulla Kanerva and Marjaana Karhu and Juha Lagerbom and Anna Kronl{\"o}f and Mari Honkanen and Erja Turunen and Tarja Laitinen", note = "EXT={"}Kanerva, Ulla{"} EXT={"}Lagerbom, Juha{"}", year = "2016", month = "4", day = "1", doi = "10.1016/j.ijrmhm.2015.11.014", language = "English", volume = "56", pages = "69--75", journal = "International Journal of Refractory Metals and Hard Materials", issn = "0958-0611", publisher = "Elsevier", }
@article{958f21309c864ed8bc976a3cc90cd5d4, title = "DFT simulations and microkinetic modelling of 1-pentyne hydrogenation on Cu20 model catalysts", abstract = "Adsorption and dissociation of H2 and hydrogenation of 1-pentyne on neutral and anionic Cu20 clusters have been investigated using the density functional theory and microkinetic modelling. Molecular adsorption of H2 is found to occur strictly at atop sites. The H2 dimer is activated upon adsorption, and the dissociation occurs with moderate energy barriers. The dissociated H atoms reside preferentially on 3-fold face and 2-fold edge sites. Based on these results, the reaction paths leading to the partial and total hydrogenation of 1-pentyne have been studied step-by-step. The results suggest that copper clusters can display selective activity on the hydrogenation of alkyne and alkene molecules. The hydrogenated products are more stable than the corresponding initial reactants following an energetic staircase with the number of added H atoms. Stable semi-hydrogenated intermediates are formed before the partial (1-pentene) and total (pentane) hydrogenation stages of 1-pentyne. The microkinetic model analysis shows that C5H10 is the dominant product. Increasing the reactants (C5H8/H2) ratio enhances the formation of products (C5H10 and C5H12).", keywords = "Adsorption and dissociation, Cluster model, Density functional theory, Heterogeneous catalysis, Hydrogenation", author = "Li Ma and Marko Melander and Timo Weckman and Saana Lipasti and Kari Laasonen and Jaakko Akola", note = "INT=fys,{"}Ma, Li{"}", year = "2016", month = "4", day = "1", doi = "10.1016/j.jmgm.2016.02.007", language = "English", volume = "65", pages = "61--70", journal = "Journal of Molecular Graphics and Modelling", issn = "1093-3263", publisher = "Elsevier", }
@article{78ac6907bb39467991495b2934587cb3, title = "Stability and Function at High Temperature. What Makes a Thermophilic GTPase Different from Its Mesophilic Homologue", abstract = "Comparing homologous enzymes adapted to different thermal environments AIDS to shed light on their delicate stability/function trade-off. Protein mechanical rigidity was postulated to secure stability and high-temperature functionality of thermophilic proteins. In this work, we challenge the corresponding-state principle for a pair of homologous GTPase domains by performing extensive molecular dynamics simulations, applying conformational and kinetic clustering, as well as exploiting an enhanced sampling technique (REST2). While it was formerly shown that enhanced protein flexibility and high temperature stability can coexist in the apo hyperthermophilic variant, here we focus on the holo states of both homologues by mimicking the enzymatic turnover. We clearly show that the presence of the ligands affects the conformational landscape visited by the proteins, and that the corresponding state principle applies for some functional modes. Namely, in the hyperthermophilic species, the flexibility of the effector region ensuring long-range communication and of the P-loop modulating ligand binding are recovered only at high temperature.", author = "Marina Katava and Maria Kalimeri and Guillaume Stirnemann and Fabio Sterpone", year = "2016", month = "3", day = "17", doi = "10.1021/acs.jpcb.6b00306", language = "English", volume = "120", pages = "2721--2730", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "10", }
@article{ffb93fddc2864c3a823adc328144d05d, title = "Phenothiazine and carbazole substituted pyrene based electroluminescent organic semiconductors for OLED devices", abstract = "Due to their easy availability, low cost and opportunities for exploiting reactions of bromo substituents, 1,3,6,8-tetrabromopyrene has attracted major attention in the organic electronics community for designing and constructing novel classes of pyrene based organic semiconducting functional materials. In the present work, 1,3,6,8-tetrabromo pyrene was transformed into the corresponding tetrasubstituted carbazole and phenothiazine derivatives using the classical Suzuki coupling reaction. These newly synthesized materials with a carbazole substituent (PY-CA) and a phenothiazine substituent (PY-PH) were characterised thoroughly and were successfully used as an active light-emitting layer in organic light emitting diodes which resulted in blue and green emission with promising device performance. PY-CA exhibited the maximum brightness at around 2500 cd m-2 and the power efficiency of 1.5 lm W-1 while that of PY-PH exhibited 2116 cd m-2 and 0.45 lm W-1 respectively.", author = "Salunke, {Jagadish K.} and Wong, {F. L.} and Krishna Feron and Sergei Manzhos and Lo, {Ming Fai} and Durgaprasad Shinde and Abhijeet Patil and Lee, {C. S.} and Roy, {V. A L} and Prashant Sonar and Wadgaonkar, {Prakash P.}", year = "2016", month = "2", day = "7", doi = "10.1039/c5tc03690a", language = "English", volume = "4", pages = "1009--1018", journal = "Journal of Materials Chemistry C", issn = "2050-7526", publisher = "Royal Society of Chemistry", number = "5", }
@article{3c1fbb45512547cdb929066c19bccef9, title = "Guanidinium Pairing Facilitates Membrane Translocation", abstract = "Ab initio free energy calculations of guanidinium pairing in aqueous solution confirm the counterintuitive conjecture that the like-charge ion pair is thermodynamically stable. Transferring the guanidinium pair to the inside of a POPC lipid bilayer, like-charge ion pairing is found to occur also inside the membrane defect. It is found to contribute to the nonadditivity of ion transfer, thereby facilitating the presence of ions inside the bilayer. The effect is quantified by free energy decomposition and comparison with ammonium ions, which do not form a stable pair. The presence of two charges inside the center of the bilayer leads to the formation of a pore. Potential consequences for cell penetrating peptides and ion conduction are drawn.", author = "Christoph Allolio and Katarina Baxova and Mario Vazdar and Pavel Jungwirth", note = "EXT={"}Vazdar, Mario{"}", year = "2016", month = "1", day = "14", doi = "10.1021/acs.jpcb.5b10404", language = "English", volume = "120", pages = "143--153", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "1", }
@article{6c5d3d39977a4d5b9f6d6e6d953c4c29, title = "Chemical and bacterial leaching of metals from a smelter slag in acid solutions", abstract = "The purpose of this study was to assess the dissolution of Si, Fe, Cu and Zn from a smelter slag sample under acidic chemical and bacterial leaching conditions. The Cu-containing solid phases were Cu-sulfides (57{\%} distribution), fayalite (18{\%}) and metallic Cu (16{\%}). Zn was mostly associated with fayalite, magnetite and Na-silicate phases (Σ94{\%}). Two mixed cultures (HB1 and HB2) were enriched from samples taken from the slag lagoon site at the smelter location. Comparable results of metal dissolution were obtained with the two mixed cultures. The enrichment culture HB1 was characterized further by denaturing gradient gel electrophoresis (DGGE) of polymerase chain reaction amplified 16S rRNA genes. Based on the 16S rRNA gene sequences, culture HB1 contained at least Acidithiobacillus ferrivorans and Alicyclobacillus cycloheptanicus, with sequences of three DGGE bands matching distantly with Alicyclobacillus tolerans and Alicyclobacillus herbarium in the database. Alicyclobacillus spp. have not been previously associated with slag lagoons or slag bioleaching. Approximately 80{\%} Cu and 25{\%} Zn were dissolved from the slag (10{\%} pulp) in shake flasks when S0 was provided for the bacteria to produce H2SO4. Bioleaching in stirred tanks was conducted at controlled pH values and was practiced at pH levels promoting metal dissolution and suppressing iron and silicate solubilization from fayalite and Na-silicate. Chemical leaching at pH 2.3-4.0 did not yield substantial dissolution of valuable metals.", keywords = "Acidithiobacillus, Alicyclobacillus, Bacterial leaching, Bioleaching, Chemical leaching, Smelter slag", author = "Kaksonen, {Anna H.} and Silja S{\"a}rkij{\"a}rvi and Puhakka, {Jaakko A.} and Esa Peuraniemi and Saku Junnikkala and Tuovinen, {Olli H.}", year = "2016", doi = "10.1016/j.hydromet.2015.10.032", language = "English", volume = "159", pages = "46--53", journal = "Hydrometallurgy", issn = "0304-386X", publisher = "Elsevier", }
@article{b8e67c9331ca4c00a0bd5a661d04f204, title = "Compatibilization of natural rubber/nitrile rubber blends by sol–gel nano-silica generated by in situ method", abstract = "Abstract: Controlled growth of in situ silica, into natural rubber (NR)/nitrile rubber (NBR) blend (40/60 composition by weight) following solution sol–gel method, results in a coherent blend morphology with enhanced composite properties. Similar composites, i.e., in situ silica-filled NR/NBR blend (40/60 by weight), showed better mechanical properties than any other composition that were prepared by soaking sol–gel method in earlier study. However, silica content in the rubber blend was limited to 20 phr (parts per hundred parts of rubber) and could not be increased under experimental condition following soaking sol–gel method. In the present work, silica content is increased (up to 30 phr) beyond that limit for the same blend composition. Accordingly, mechanical properties of the NR/NBR composites are improved. Use of a silane coupling agent, viz., bis-(3-triethoxysilylpropyl)-tetra sulfide, in the reactive sol–gel system during in situ silica generation brings in remarkable effect in silica distribution, rubber–filler interaction and mechanical properties of the composites. TEM micrographs of the selected composites reveal that silica is mostly grown at the interfacial region, when silane is used in particular. This results in further enhancement in mechanical properties and compatibility of the blend at the same silica content as evident from stress–strain and dynamic mechanical analysis studies. The reinforcement of effect in situ silica is assessed by Guth–Gold equation and modified form of Guth equation (with shape factor f = 2.53). The results are supported by the detailed studies on rheological, morphological, mechanical and viscoelastic properties of the composites. Graphical Abstract: [Figure not available: see fulltext.]", keywords = "In situ silica, Reinforcement, Rubber blend, Rubber–filler interaction, Silane treatment, Sol–gel method", author = "Bansod, {Naresh D.} and Kapgate, {Bharat P.} and Chayan Das and Amit Das and Debdipta Basu and Debnath, {Subhas Chandra}", year = "2016", doi = "10.1007/s10971-016-4114-0", language = "English", volume = "80", pages = "548–559", journal = "JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY", issn = "0928-0707", publisher = "Springer Verlag", number = "2", }
@article{f59fbfac89c642fa82da8abbb5ab5c0b, title = "Dissolution behavior of the bioactive glass S53P4 when sodium is replaced by potassium, and calcium with magnesium or strontium", abstract = "The initial dissolution behavior of glasses based on bioactive glass S53P4 was studied with a dynamic measurement setup in a Tris-buffered solution. The glass composition was modified systematically on a molar basis by replacing sodium oxide with potassium oxide (0-100{\%} K) and calcium oxide with magnesium (0-18{\%} Mg) or strontium oxide (0-100{\%} Sr). The concentrations of the ions dissolving from the glasses were measured continuously on-line in the fluid flow for 15 to 25 min using an inductively coupled plasma emission optical spectrometer. This method enabled attainment of detailed information on the initial dissolution mechanisms without the, for bioactive glasses typical, interference of apatite layer formation. The results showed that initial dissolutions of sodium and potassium were markedly higher from the mixed alkali oxide glasses than from the compositions containing only one alkali oxide. Introducing MgO in S53P4 caused a minor decrease in the dissolution rates of all ions. The glass containing 3 mol{\%} of MgO showed the best chemical durability. In contrast, replacing CaO gradually with SrO increased the dissolution rates of all ions. The glasses with the highest replacement of CaO with SrO showed rapid release of both Sr and Na ions. The results corroborate the overall knowledge of glass durability and can be utilized to design bioactive glasses with controlled ion release rate for tissue engineering applications.", keywords = "Bioactive glass, Chemical durability, Dynamic solution, Ion dissolution", author = "Leena Hupa and Susanne Fagerlund and Jonathan Massera and Leena Bj{\"o}rkvik", year = "2016", doi = "10.1016/j.jnoncrysol.2015.03.026", language = "English", pages = "41--46", journal = "Journal of Non-Crystalline Solids", issn = "0022-3093", publisher = "Elsevier", }
@inproceedings{3a3d02a0e0504200b70b89f0ae97ba99, title = "Improved properties for packaging materials by nanoscale surface modification and ALD barrier coating", author = "Johanna Lahti and Juho Lavonen and Kimmo Lahtinen and Petri Johansson and Tarja Sepp{\"a}nen and Cameron, {David C.}", year = "2016", language = "English", volume = "2", pages = "684--706", booktitle = "TAPPI International Conference on Nanotechnology for Renewable Materials 2016", publisher = "TAPPI Press", address = "United States", }
@article{742c27cf9e074e139db6fa969df7a909, title = "Microstructural and abrasion wear characteristics of laser-clad tool steel coatings", abstract = "Several different tool steel grades were deposited on mild steel by the laser-cladding process with coaxial powder feeding. With bidirectional scanning pattern, most of the grades were deposited crack-free with hardness up to 1000 HV without additional preheating. In a 3-body abrasion wear study, the laser clad Ralloy{\circledR} WR6 with significant portion of retained austenite exhibited superior abrasive wear resistance compared with the predominantly martensitic tool steel coatings (M2, M4, H13, HS-23, HS-30) and the reference material, Raex{\circledR} Ar500 wear resistant steel. The abrasion wear resistance of austenitic–martensitic WR6 tool steel was further enhanced by the external addition of 20{\%} volume percentage of relatively large (45–106 µm) vanadium carbides. In single point scratch tests, predominantly martensitic tool steels outperformed austenitic–martensitic tool steels and wear resistant steel. The differences in wear performances were explained by different wear mechanisms and types of contact between the abrasive and the surface.", keywords = "3-Body abrasion wear, Laser cladding, Metal matrix composite, Scratch test, Tool steel, Wear resistant steel", author = "J. Tuominen and J. N{\"a}kki and H. Pajukoski and L. Hyv{\"a}rinen and P. Vuoristo", note = "EXT={"}N{\"a}kki, J.{"} INT=mol,{"}Pajukoski, H.{"}", year = "2016", doi = "10.1080/02670844.2016.1180496", language = "English", volume = "32", pages = "923--933", journal = "Surface Engineering", issn = "0267-0844", publisher = "Taylor & Francis Ltd", number = "12", }
@article{8d78b55c68fe4ccabe8170b1c99a836c, title = "Photoresponsive liquid-crystalline polymer films bilayered with an inverse opal structure", abstract = "An inverse opal film was layered to a photodeformable film, and its photoresponsive behavior was investigated. This bilayer films composed of colorless photonic crystal using inverse opal structures and colored photoresponsive layers with azobenzene-containing CLCP.", keywords = "Bragg diffraction, Inverse opal structure, Photoresponsive film", author = "Norihisa Akamatsu and Miho Aizawa and Ryoichi Tatsumi and Kyohei Hisano and Arri Priim{\"a}gi and Atsushi Shishido", year = "2016", doi = "10.2494/photopolymer.29.145", language = "English", volume = "29", pages = "145--148", journal = "JOURNAL OF PHOTOPOLYMER SCIENCE AND TECHNOLOGY", issn = "0914-9244", publisher = "Tokai University", number = "1", }
@article{a27f7a972998405784706831b12cc4ad, title = "Rapid and sensitive detection of norovirus antibodies in human serum with a biolayer interferometry biosensor", abstract = "Here, we describe the use of a biolayer interferometry biosensor for the fast and sensitive detection of virus-specific antibodies from human serum samples. Norovirus-like particles and norovirus P-particles were used to functionalise the biosensor tip. The detection of antibodies directly from serum samples was challenging, but the addition of a metal chelator (DAB) combined with an anti-human horseradish peroxidase-tagged antibody enabled enhanced detection of virus-specific antibodies in serum dilutions up to 1:100,000. Biolayer interferometry provides results faster than an ELISA, with results in as little as 10-20 min when using pre-functionalised sensors. Therefore, biolayer interferometry combined with DAB enhancement offers an attractive method for quick and sensitive quantification of biomolecules from complicated sample matrices.", keywords = "Biolayer interferometry, Fast diagnostics, Non-labelled detection, Norovirus, P-particles, Virus-like particles (VLPs)", author = "Sanna Auer and Tiia Koho and Hanni Uusi-Kerttula and Timo Vesikari and Vesna Blazevic and Hyt{\"o}nen, {Vesa P.}", year = "2015", month = "12", day = "31", doi = "10.1016/j.snb.2015.06.088", language = "English", volume = "221", pages = "507--514", journal = "Sensors and Actuators B: Chemical", issn = "0925-4005", publisher = "Elsevier Science", }
@article{3b99bb15c5e84144aff8ab4e37951cb3, title = "Effect of rubber polarity on selective wetting of carbon nanotubes in ternary blends", abstract = "Based on atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) analysis of the rubber-filler gel (wetting concept) the kinetics of selective wetting of carbon nanotubes (CNTs) in ternary styrene butadiene rubber (SBR)/butadiene rubber (BR)/natural rubber (NR) blends was qualitatively and quantitatively characterized. Almost all CNTs are found to be wetted by the non-polar NR but not by the other non-polar rubber like BR or weakly polar SBR. It was proposed that phospholipids, which are linked to the α-terminal of NR can interact with the CNT surface through cation-π interactions forming strong bonding between NR and CNTs. Using the corrected surface tension value of NR, which involves the effect of phospholipids found in our previous work the selective wetting of CNTs in ternary rubber blends can be well predicted using the Z-model for a thermodynamic equilibrium state. By replacing the non-polar BR by a polar rubber like nitrile butadiene rubber (NBR) as a blend component CNTs are wetted by NBR slightly more than by NR thanks to the strong interaction between CNTs and nitrile groups of NBR. SBR remains unbound to CNTs in both blends.", keywords = "Carbon nanotubes, Manocomposites, Rubber blends, Selective filler wetting", author = "Le, {H. H.} and M. Parsaker and Sriharish, {M. N.} and S. Henning and M. Menzel and S. Wie{\ss}ner and A. Das and Do, {Q. K.} and G. Heinrich and Radusch, {H. J.}", year = "2015", month = "11", day = "1", doi = "10.3144/expresspolymlett.2015.87", language = "English", volume = "9", pages = "960--971", journal = "Express Polymer Letters", issn = "1788-618X", publisher = "BME-PT and GTE", number = "11", }
@article{e235e07ac9574d54a589c507bba21988, title = "Processing and characterization of phosphate glasses containing CaAl2O4:Eu2+,Nd3+ and SrAl2O4:Eu2+,Dy3+ microparticles", abstract = "In this paper, phosphate based glasses with persistent luminescence properties were processed using standard melting process in air by adding SrAl2O4:Eu2+,Dy3+ or CaAl2O4:Eu2+,Nd3+ in the glass batch before melting. All produced glasses were characterized using SEM/EDXA, Raman spectroscopy and photoluminescence. We discuss the effect of melting conditions (temperature and duration of the melting) on the persistent luminescence properties of the microparticles containing glasses. It is demonstrated that the melting in air allows for the preparation of glasses with persistent luminescence if the melting conditions are carefully controlled.", keywords = "Persistent luminescence, Phosphate glasses, SrAl2O4:Eu2+,Dy3+ and CaAl2O4:Eu2+,Nd3+ microparticles", author = "J. Massera and M. Gaussiran and P. Gluchowski and M. Lastusaari and L. Hupa and L. Petit", year = "2015", month = "11", day = "1", doi = "10.1016/j.jeurceramsoc.2015.06.031", language = "English", volume = "35", pages = "3863--3871", journal = "Journal of the European Ceramic Society", issn = "0955-2219", publisher = "Elsevier", number = "14", }
@article{20a8363d54f7473481536cb40ccfddc4, title = "Photomechanical Energy Transfer to Photopassive Polymers through Hydrogen and Halogen Bonds", abstract = "The supramolecular assembly of photoactive azobenzenes with passive polymers via halogen or hydrogen bonding is a cost-effective way to design materials for various photomechanical applications that convert light energy directly into macroscopic motion, for instance, in all-optical surface patterning and photochemical imaging of plasmonic structures. To elucidate the molecular-level origins of this motion, we show, by coupling dynamic infrared spectroscopy to a photo-orientation setup, that supramolecular bonds above a certain interaction strength threshold are photostable under vigorous photoisomerization cycling and capable of translating the photo-orientation of azobenzenes into the orientation of nonabsorbing host polymer side chains. A correlation is found between azobenzene photoinduced molecular orientation and macroscopic all-optical surface patterning efficiency. The improved performance of halogen-bonded systems in photopatterning applications can be related to the absence of a plasticizing effect on the polymer matrix, which may enable the material to retain an optimal glass transition temperature, in contrast to hydrogen-bonded and nonbonded references. Thus, our results provide design guidelines in terms of the nature and strength of the supramolecular interaction and of the degree of azo functionalization needed to optimize the motion transfer to passive polymers.", author = "Jaana Vapaavuori and Heikkinen, {Ismo T S} and Valentina Dichiarante and Giuseppe Resnati and Pierangelo Metrangolo and Sabat, {Ribal Georges} and Bazuin, {C. Geraldine} and Arri Priimagi and Christian Pellerin", note = "EXT={"}Vapaavuori, Jaana{"}", year = "2015", month = "10", day = "27", doi = "10.1021/acs.macromol.5b01813", language = "English", volume = "48", pages = "7535--7542", journal = "Macromolecules", issn = "0024-9297", publisher = "American Chemical Society", number = "20", }
@article{57149610fc274d96ba8e5ac68f88333c, title = "In Situ Photocontrol of Block Copolymer Morphology during Dip-Coating of Thin Films", abstract = "We demonstrate a unique combination of simultaneous top-down and bottom-up control of the morphology of block copolymer films by application of in situ optical irradiation during dip-coating. A light-addressable and block-selective small molecule, 4-butyl-4′-hydroxyazobenzene (BHAB), is introduced into a diblock copolymer of polystyrene and poly(4-vinylpyridine) (PS-P4VP) of 28.4 wt {\%} P4VP via supramolecular chemistry, notably by hydrogen bonding to P4VP. We show that the spherical morphology of thin films dip-coated from a THF solution at slow withdrawal rates in the dark convert to cylindrical morphology when dip-coated under illumination. This is attributed to volume expansion of the P4VP/BHAB phase due to trans-cis photoisomerization combined with a light-induced increase in BHAB uptake in the film. The demonstrated photocontrol highlights the potential of dip-coating as a scalable film preparation method that can be easily coupled with external stimuli to direct nanostructured self-assembly in the films as solvent evaporates.", author = "Jaana Vapaavuori and Josu{\'e} Grosrenaud and Christian Pellerin and Bazuin, {C. Geraldine}", year = "2015", month = "10", day = "20", doi = "10.1021/acsmacrolett.5b00483", language = "English", volume = "4", pages = "1158--1162", journal = "ACS Macro Letters", issn = "2161-1653", publisher = "American Chemical Society ACS", number = "10", }
@article{815d0d4d993744029c946ab96ac2a586, title = "Comparison of laboratory rolling-sliding wear tests with in-service wear of nodular cast iron rollers against wire ropes", abstract = "The present work describes the wear behaviour of nodular cast iron in rolling-sliding contact with steel wire ropes and steel wires in laboratory and in-service conditions. In each of the studied examples, the wear had proceeded through a surface fatigue process, in which inter-nodular crack propagation and simultaneous deformation in a thin sub-surface zone had resulted in the formation of ferrous scales consisting of material from the metal matrix of the cast iron. The scale layers of the wear surface were oriented towards the direction of the sliding component of the motion, and the spalling of the scales was identified as the dominating mechanism for material removal from the wear surface. The initiation behaviour of the inter-nodular cracks was analysed by crack measurements and statistical analysis of the depths and initiation angles of the cracks in relation to the wear surface. The initiation depths of the cracks increased with increasing contact pressure. Roller samples from in-service and from the component wear tests showed closely similar distributions of the crack depths and crack initiation angles. The sample from the twin-disc test showed aspects of cracking behaviour that were typical of both the rolling and the sliding direction of the roller samples.", keywords = "Contact mechanics, Nodular cast iron, Rolling contact fatigue, Rolling-sliding, Wear testing, Wire rope", author = "V. Oksanen and K. Valtonen and P. Andersson and A. Vaajoki and A. Laukkanen and K. Holmberg and Kuokkala, {V. T.}", year = "2015", month = "10", day = "15", doi = "10.1016/j.wear.2015.07.006", language = "English", volume = "340-341", pages = "73--81", journal = "Wear", issn = "0043-1648", publisher = "Elsevier", }
@article{62750e4ac62e42e893a93d1ba3c87e71, title = "Characterization of thermally aged polyetheretherketone fibres: Mechanical, thermal, rheological and chemical property changes", abstract = "This paper investigates the effects of thermal degradation on polyetheretherketone (PEEK) fibres. PEEK samples were aged at a constant temperature of 250 °C for 1-128 days and characterized with mechanical tests, FTIR (Fourier Transform Infrared Spectroscopy), DSC (Differential Scanning Calorimetry), rheology, TGA (Thermogravimetric Analysis), SEM (Scanning Electron Microscopy), and UV-Vis diffuse reflectance spectroscopy. The short-term thermal annealing had a positive effect on the mechanical properties, due to the formation and growth of secondary crystals. Crosslinking in the material was verified by rheological inspections. The crosslinking increased the mechanical strength and modulus but reduced the elongation at break of the fibres. FTIR tests showed that carbonyl and hydroxyl groups were slowly formed on the surface of the fibres while ring opening reactions took place. The thermal ageing reduced the thermal stability of PEEK. The decreased stability was observed in the decomposition onset temperature after 8 d and in the melting point and the glass transition temperature after 32 d. The first signs of degradation, crosslinking, embrittlement, and reduced thermal stability, were visible roughly after 8 d of ageing, whereas the deterioration in general usability occurred after 64 d.", keywords = "Fibre, PEEK, Thermal degradation", author = "Ville Myll{\"a}ri and Tero-Petri Ruoko and Jyrki Vuorinen and Helge Lemmetyinen", note = "ORG=mol,0.75 ORG=keb,0.25 24 kk embargo (post-print)", year = "2015", month = "10", day = "1", doi = "10.1016/j.polymdegradstab.2015.08.003", language = "English", volume = "120", pages = "419--426", journal = "Polymer Degradation and Stability", issn = "0141-3910", publisher = "Elsevier", }
@article{412d0d5ac58546698c67a0a7ad79e5df, title = "Production of sulfonated polyetheretherketone/polypropylene fibers for photoactive textiles", abstract = "New photocatalytic fibers made of sulfonated polyetheretherketone (SPEEK)/polypropylene (PP) are melt compounded and melt spun, first on laboratory scale and then on a semi-industrial scale. Fiber spinnability is optimized and the fibers are characterized using mechanical testing, electron paramagnetic resonance (EPR) spectroscopy, and scanning electron microscopy (SEM). According to the results, the fiber spinnability remains at a good level up to 10 wt {\%} SPEEK concentration. Optimal processing temperature is 200C due to the thermal degradation at higher temperatures. EPR measurements show good and long-lasting photoactivity after the initial irradiation but also decay in the radical intensity during several irradiation cycles. Mechanical tenacity of the SPEEK/PP 5:95 fiber is approximately 20{\%} lower than for otherwise similar PP fiber. The fiber is a potential alternative to compete against TiO2-based products but more research needs to be done to verify the real-life performance.", keywords = "blends, fibers, functionalization of polymers, photochemistry, textiles", author = "Ville Myll{\"a}ri and Enrico Fatarella and Marco Ruzzante and Rebecca Pogni and Baratto, {Maria Camilla} and Mikael Skrifvars and Seppo Syrj{\"a}l{\"a} and Pentti J{\"a}rvel{\"a}", note = "ORG=mol,0.5 ORG=mei,0.5 EXT={"}Skrifvars, Mikael{"}", year = "2015", month = "10", day = "1", doi = "10.1002/app.42595", language = "English", volume = "132", journal = "Journal of Applied Polymer Science", issn = "0021-8995", publisher = "Wiley", number = "39", }
@article{b34134808d744a0cb6727235d88257f8, title = "PIP2 and Talin Join Forces to Activate Integrin", abstract = "Integrins are major players in cell adhesion and migration, and malfunctions in controlling their activity are associated with various diseases. Nevertheless, the details of integrin activation are not completely understood, and the role of lipids in the process is largely unknown. Herein, we show using atomistic molecular dynamics simulations that the interplay of phosphatidylinositol 4,5-bisphosphate (PIP2) and talin may directly alter the conformation of integrin αIIbβ3. Our results provide a new perspective on the role of PIP2 in integrin activation and indicate that the charged PIP2 lipid headgroup can perturb a clasp at the cytoplasmic face of the integrin heterodimer.", author = "Adam Orlowski and Sampo Kukkurainen and Annika P{\"o}yry and Sami Rissanen and Ilpo Vattulainen and Hyt{\"o}nen, {Vesa P.} and Tomasz R{\'o}g", note = "AUX=fys,{"}P{\"o}yry, Annika{"}", year = "2015", month = "9", day = "24", doi = "10.1021/acs.jpcb.5b06457", language = "English", volume = "119", pages = "12381--12389", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "38", }
@article{85fa4c0939544f7098e134de0c2357eb, title = "Effect of spraying parameters on the microstructural and corrosion properties of HVAF-sprayed Fe-Cr-Ni-B-C coatings", abstract = "Thermally sprayed Fe-based coatings have been extensively studied as future solution in order to replace more expensive, harmful and environmentally dangerous Ni- and WC-based coatings for several industrial applications where high corrosion and wear resistance are required. The aim of the present study is to investigate the effect of spraying parameters on the microstructure and the corrosion resistance of Fe-based coatings manufactured with the High Velocity Air Fuel (HVAF) thermal spray process. Six sets of thermal spraying parameters have been chosen and their effect on the overall quality of coatings was investigated. All HVAF coatings showed comparably dense microstructure with near-zero oxidation, proving the high quality of the deposition process. However, higher anti-corrosion and mechanical properties were achieved by increasing the spraying air pressure and decreasing the particle feeding rate without altering the thickness and the overall deposition rate. Powder feeding rate was reported to have a remarkable effect on microstructure and corrosion properties. Coatings with beneficial compressive residual stresses were successfully obtained by increasing air pressure during spraying which resulted in improved microstructural and corrosion properties.", keywords = "Corrosion behaviour, Fe-based coating, HVAF, Structure", author = "A. Milanti and V. Matikainen and H. Koivuluoto and G. Bolelli and L. Lusvarghi and P. Vuoristo", year = "2015", month = "9", day = "15", doi = "10.1016/j.surfcoat.2015.07.018", language = "English", volume = "277", pages = "81--90", journal = "Surface & Coatings Technology", issn = "0257-8972", publisher = "Elsevier", }
@article{4241a0785f9747a685c71a4a5fa57c25, title = "Molecular Design of Light-Responsive Hydrogels, for in Situ Generation of Fast and Reversible Valves for Microfluidic Applications", abstract = "Reversible light-responsive hydrogel valves with response characteristics compatible for microfluidics have been obtained by optimization of molecular design of spiropyran photoswitches and gel composition. Self-protonating gel formulations were exploited, wherein acrylic acid was copolymerized in the hydrogel network as an internal proton donor, to achieve a swollen state of the hydrogel in water at neutral pH. Light-responsive properties were endowed upon the hydrogels by copolymerization of spiropyran chromophores, using electron withdrawing and donating groups to tune the gel-swelling and shrinkage behavior. In all cases, the shrinkage was determined by the water diffusion rate, while for the swelling the isomerization kinetics is the rate-determining step. For one hydrogel, reversible and reproducible volume changes were observed. Finally, gel-valves integrated within microfluidic channels were fabricated, allowing reversible and repeatable operation, with opening and closing of the valve in minutes.", author = "{Ter Schiphorst}, Jeroen and Simon Coleman and Stumpel, {Jelle E.} and {Ben Azouz}, Aymen and Dermot Diamond and Schenning, {Albertus P. H. J.}", year = "2015", month = "9", day = "8", doi = "10.1021/acs.chemmater.5b01860", language = "English", volume = "27", pages = "5925--5931", journal = "Chemistry of Materials", issn = "0897-4756", publisher = "American Chemical Society", number = "17", }
@article{e046296b130444069c0d00fd07671331, title = "Unintentional boron contamination of MBE-grown GaInP/AlGaInP quantum wells", abstract = "The effects of unintentional boron contamination on optical properties of GaInP/AlGaInP quantum well structures grown by molecular beam epitaxy (MBE) are reported. Photoluminescence and secondary-ion mass spectrometry (SIMS) measurements revealed that the optical activity of boron-contaminated quantum wells is heavily affected by the amount of boron in GaInP/AlGaInP heterostructures. The boron concentration was found to increase when cracking temperature of the phosphorus source was increased. Boron incorporation was enhanced also when aluminum was present in the material.", keywords = "A1. Defects, A1. Impurities, A3. Molecular beam epitaxy, B1. Phosphides, B2. Semiconducting III-V materials", author = "Antti Tukiainen and Jari Likonen and Lauri Toikkanen and Tomi Leinonen", year = "2015", month = "9", day = "1", doi = "10.1016/j.jcrysgro.2015.02.048", language = "English", volume = "425", pages = "60--63", journal = "Journal of Crystal Growth", issn = "0022-0248", publisher = "Elsevier", }
@article{ba3a69c45d854693bda8291ad2450adf, title = "Effect of Phosphatidic Acid on Biomembrane: Experimental and Molecular Dynamics Simulations Study", abstract = "We consider the impact of phosphatidic acid (namely, 1,2-dioleoyl-sn-glycero-3-phosphate, DOPA) on the properties of a zwitterionic (1,2-dipalmitoyl-sn-glycero-3-phosphocholine, DPPC) bilayer used as a model system for protein-free cell membranes. For this purpose, experimental measurements were performed using differential scanning calorimetry and the Langmuir monolayer technique at physiological pH. Moreover, atomistic-scale molecular dynamics (MD) simulations were performed to gain information on the mixed bilayer's molecular organization. The results of the monolayer studies clearly showed that the DPPC/DOPA mixtures are nonideal and the interactions between lipid species change from attractive, at low contents of DOPA, to repulsive, at higher contents of that component. In accordance with these results, the MD simulations demonstrated that both monoanionic and dianionic forms of DOPA have an ordering and condensing effect on the mixed bilayer at low concentrations. For the DOPA monoanions, this is the result of both (i) strong electrostatic interactions between the negatively charged oxygen of DOPA and the positively charged choline groups of DPPC and (ii) conformational changes of the lipid acyl chains, leading to their tight packing according to the so-called umbrella model, in which large headgroups of DPPC shield the hydrophobic part of DOPA (the conical shape lipid) from contact with water. In the case of the DOPA dianions, cation-mediated clustering was observed. Our results provide a detailed molecular-level description of the lipid organization inside the mixed zwitterionic/PA membranes, which is fully supported by the experimental data.", author = "Urszula Kwolek and Waldemar Kulig and Paweł Wydro and Maria Nowakowska and Tomasz R{\'o}g and Mariusz Kepczynski", year = "2015", month = "8", day = "6", doi = "10.1021/acs.jpcb.5b03604", language = "English", volume = "119", pages = "10042--10051", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "31", }
@article{7259a667869c4d4482667fc6679a1050, title = "Evaluation of crushing strength of spray-dried MgAl2O4 granule beds", abstract = "The crushing strengths of four different experimental magnesium aluminate spinel (MgAl2O4) granule beds were monitored with the axial die pressing test after heat treatments. Precursor, magnesium hydroxide (Mg(OH)2) and magnesium oxide (MgO) as Mg precursor and aluminium oxide hydroxide Al(O)OH and α-Al2O3 as Al precursor, were used for experimental granules, which were manufactured via a dispersion manufacturing and spray-drying process. After spray-drying, granules were heat treated in air at 1000, 1100, 1200, 1300 and 1400 °C. In order to understand the potential effect of precursor, phase structure, morphology, particle size distribution and density of granules on crushing strength behaviour, scanning X-ray diffraction (XRD) was used together with electron microscopy (SEM) and laser diffraction (LDPA) for characterisation. All precursor mixtures formed spherical granules during the spray-drying process and pure spinel phase structure during heat treatment. The crushing strength test results indicated that the Al precursor clearly affected the crushing strength behaviour of experimental granule beds. The highest strength was observed for granule beds with Al(O)OH) as Al and Mg(OH)2 as Mg precursor.", keywords = "Axial pressing, Granule, MgAl2O4 spinel, The crushing strength", author = "Ulla Kanerva and Tomi Suhonen and Juha Lagerbom and Erkki Lev{\"a}nen", note = "EXT={"}Lagerbom, Juha{"} EXT={"}Kanerva, Ulla{"}", year = "2015", month = "8", day = "1", doi = "10.1016/j.ceramint.2015.03.056", language = "English", volume = "41", pages = "8494--8500", journal = "Ceramics International", issn = "0272-8842", publisher = "Elsevier", number = "7", }
@article{7e7717b46029402dbeaecb84fce22d61, title = "Nonlinear Optical Properties of Fluorescent Dyes Allow for Accurate Determination of Their Molecular Orientations in Phospholipid Membranes", abstract = "Several methods based on single- and two-photon fluorescence detected linear dichroism have recently been used to determine the orientational distributions of fluorescent dyes in lipid membranes. However, these determinations relied on simplified descriptions of nonlinear anisotropic properties of the dye molecules, using a transition dipole-moment-like vector instead of an absorptivity tensor. To investigate the validity of the vector approximation, we have now carried out a combination of computer simulations and polarization microscopy experiments on two representative fluorescent dyes (DiI and F2N12S) embedded in aqueous phosphatidylcholine bilayers. Our results indicate that a simplified vector-like treatment of the two-photon transition tensor is applicable for molecular geometries sampled in the membrane at ambient conditions. Furthermore, our results allow evaluation of several distinct polarization microscopy techniques. In combination, our results point to a robust and accurate experimental and computational treatment of orientational distributions of DiI, F2N12S, and related dyes (including Cy3, Cy5, and others), with implications to monitoring physiologically relevant processes in cellular membranes in a novel way.", author = "Štěp{\'a}n Timr and Jiř{\'i} Brabec and Alexey Bondar and Tom{\'a}š Ryba and Miloš Železn{\'y} and Josef Lazar and Pavel Jungwirth", note = "EXT={"}Bondar, Alexey{"}", year = "2015", month = "7", day = "30", doi = "10.1021/acs.jpcb.5b05123", language = "English", volume = "119", pages = "9706--9716", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "30", }
@article{cf5e33c2d49a43afb0eb0fd6fbed016c, title = "Role of Internal Water on Protein Thermal Stability: The Case of Homologous G Domains", abstract = "In this work, we address the question of whether the enhanced stability of thermophilic proteins has a direct connection with internal hydration. Our model systems are two homologous G domains of different stability: the mesophilic G domain of the elongation factor thermal unstable protein from E. coli and the hyperthermophilic G domain of the EF-1α protein from S. solfataricus. Using molecular dynamics simulation at the microsecond time scale, we show that both proteins host water molecules in internal cavities and that these molecules exchange with the external solution in the nanosecond time scale. The hydration free energy of these sites evaluated via extensive calculations is found to be favorable for both systems, with the hyperthermophilic protein offering a slightly more favorable environment to host water molecules. We estimate that, under ambient conditions, the free energy gain due to internal hydration is about 1.3 kcal/mol in favor of the hyperthermophilic variant. However, we also find that, at the high working temperature of the hyperthermophile, the cavities are rather dehydrated, meaning that under extreme conditions other molecular factors secure the stability of the protein. Interestingly, we detect a clear correlation between the hydration of internal cavities and the protein conformational landscape. The emerging picture is that internal hydration is an effective observable to probe the conformational landscape of proteins. In the specific context of our investigation, the analysis confirms that the hyperthermophilic G domain is characterized by multiple states and it has a more flexible structure than its mesophilic homologue. (Figure Presented).", author = "Obaidur Rahaman and Maria Kalimeri and Simone Melchionna and J{\'e}r{\^o}me H{\'e}nin and Fabio Sterpone", year = "2015", month = "7", day = "23", doi = "10.1021/jp507571u", language = "English", volume = "119", pages = "8939--8949", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "29", }
@article{10c0a4605d45443cac0389846bc31513, title = "Measuring optical anisotropy in poly(3,4-ethylene dioxythiophene): poly(styrene sulfonate) films with added graphene", abstract = "Abstract Graphene is a 2D nanomaterial having a great potential for applications in electronics and optoelectronics. Composites of graphene with conducting polymers have shown high performance in practical devices and their solution-processability enables low-cost and high-throughput mass manufacturing using printing techniques. Here we measure the effect of incorporation of graphene into poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) to the optical anisotropy, absorbance and conductivity of the film. Uniaxial anisotropy in PEDOT:PSS films has been thought to be caused by the spin-coating process used in fabrication. We have characterized spray- and spin-coated films using ellipsometry and total internal reflection spectroscopy, the latter especially for films too thick and uneven for ellipsometry, and show that spray-coating, similar to inkjet printing, also produces consistently anisotropic properties even in very thick and uneven films. Possible plasmonic excitations related to graphene are not seen in the films. The optical and electrical anisotropy of graphene/PEDOT:PSS enables routes to high performance devices for electronics, photonics and optoelectronics.", keywords = "PEDOT: PSS, Graphene, Anisotropy, Spectroscopy, Conducting polymer, CARBON-NANOTUBE, ELECTRONICS, OPTOELECTRONICS, CONDUCTIVITY, TRANSPARENT, PHOTONICS, GROWTH, CELLS", author = "Tommi Isoniemi and Sampo Tuukkanen and Cameron, {David C.} and Janne Simonen and Toppari, {J. Jussi}", note = "Versio ja lupa ok 13.1.2016 /KK EXT={"}Simonen, Janne{"}", year = "2015", month = "7", day = "9", doi = "10.1016/j.orgel.2015.06.037", language = "English", volume = "25", pages = "317--323", journal = "Organic Electronics", issn = "1566-1199", publisher = "Elsevier Science B.V.", }
@article{f42d2d9f65b64a6cb98a7d230cdcb1ad, title = "A comparison of rheology and FTIR in the study of polypropylene and polystyrene photodegradation", abstract = "Rheology and FTIR spectroscopy are compared as methods to study the degree of photodegradation in polypropylene (PP) and polystyrene (PS) sheets. The materials are hot pressed, artificially photo-aged with fluorescent lights for 4-2048 h and then measured with a rotational rheometer and FTIR. Both materials show a tendency for chain scission which can be seen as a reduction in viscosity. Changes in PP can be observed with both methods after 256 h of irradiation. Changes in PS become significant in rheology after 64 h but in FTIR only after 1024 h of irradiation. Due to the different chemical nature of the materials, the degradation of PS is rather linear with exposure, whereas the degradation of PP is more exponential. Using the zero shear viscosities obtained through extrapolations of the Cole-Cole and Carreau-Yasuda models, relative molecular weights are estimated with the aid of the power-law relationship between these two. These results are compared with the carbonyl indices determined from the FTIR spectra. Rheology is found to be a viable alternative for FTIR in certain situations.", keywords = "aging, degradation, rheology, thermoplastics, PHOTOOXIDATION, FILMS, PHOTOLYSIS", author = "Ville Myll{\"a}ri and Tero-Petri Ruoko and Seppo Syrj{\"a}l{\"a}", note = "ORG=mol,0.7 ORG=keb,0.2 ORG=mei,0.1", year = "2015", month = "7", day = "1", doi = "10.1002/app.42246", language = "English", volume = "132", journal = "Journal of Applied Polymer Science", issn = "0021-8995", publisher = "Wiley", number = "28", }
@article{bbe0ba219c9f49a6915824d413d6e8fd, title = "Synthesis and Photophysical Properties of Two Diazaporphyrin-Porphyrin Hetero Dimers in Polar and Nonpolar Solutions", abstract = "Two diazaporphyrin (DAP)-porphyrin hetero dimers, in β-meso and β-β configurations, were prepared to study their photoinduced intramolecular electron transfer properties. The two meso nitrogen atoms in the porphyrin ring of DAP change its redox potential, making DAP more easily reduced, compared to its porphyrin counterpart. A charge-transfer from porphyrin to DAP in both hetero dimers was verified by versatile optical spectroscopic methods. The steady-state fluorescence spectra indicated an efficient intramolecular exciplex formation for both dimers. For the β-meso dimer, ultrafast time-resolved spectroscopic methods revealed the subpicosecond formation of two types of primary short-living (1-18 ps) intramolecular exciplexes, which relaxed in toluene to form a long-living final exciplex (1.4 ns) followed by a longer-living charge transfer complex (>5 ns). However, in benzonitrile, the lifetime of the final exciplex was longer (660 ps) as was that of the charge transfer complex (180 ps). The β-β analogue formed similar short-living exciplexes in both solvents, but the final exciplex and the charge transfer state had significantly shorter lifetimes. The electrochemical redox potential measurements and density functional theory calculations supported the proposed mechanism.", author = "Fawzi Abou-Chahine and Daisuke Fujii and Hiroshi Imahori and Haruyuki Nakano and Tkachenko, {Nikolai V.} and Yoshihiro Matano and Helge Lemmetyinen", year = "2015", month = "6", day = "18", doi = "10.1021/jp510903a", language = "English", volume = "119", pages = "7328--7337", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "24", }
@article{a558919d13a64b58bc404bb10c76f55d, title = "Passive resonance sensor based method for monitoring particle suspensions", abstract = "Control of particle suspensions is needed in several modern industrial processes. A reason for the difficulty in this task has been the lack of a fast and reliable measurement. In this study, we tested the measurement of particle suspension by using a method based on a passive resonance sensor. The relative amounts of dispersing agent and aluminium oxide in the suspension were varied. The studied method yielded signals which depended on the complex permittivity of the suspension. The results indicated that we were able to measure information that can be used as feedback for the suspension preparation process. In addition, the tested instrumentation was simple and robust and thus this method may allow online measurements directly from the industrial processes.", keywords = "Complex permittivity, Inductive coupling, Passive resonance sensor, Slurry, Suspension", author = "Timo Salpavaara and Matti J{\"a}rvel{\"a}inen and Sari Sepp{\"a}l{\"a} and Teemu Yli-Hallila and Jarmo Verho and Matti Vilkko and Jukka Lekkala and Erkki Lev{\"a}nen", note = "ORG=ase,0.5 ORG=mol,0.5", year = "2015", month = "6", day = "8", doi = "10.1016/j.snb.2015.04.121", language = "English", volume = "219", pages = "324--330", journal = "Sensors and Actuators B: Chemical", issn = "0925-4005", publisher = "Elsevier Science", }
@article{040f43166da7479ab448a442f63bf06f, title = "PEGylated liposomes as carriers of hydrophobic porphyrins", abstract = "Sterically stabilized liposomes (SSLs) (PEGylated liposomes) are applied as effective drug delivery vehicles. Understanding the interactions between hydrophobic compounds and PEGylated membranes is therefore important to determine the effectiveness of PEGylated liposomes for delivery of drugs or other bioactive substances. In this study, we have combined fluorescence quenching analysis (FQA) experiments and all-atom molecular dynamics (MD) simulations to study the effect of membrane PEGylation on the location and orientation of 5,10,15,20-tetrakis(4-hydroxyphenyl)porphyrin (p-THPP) that has been used in our study as a model hydrophobic compound. First, we consider the properties of p-THPP in the presence of different fluid phosphatidylcholine bilayers that we use as model systems for protein-free cell membranes. Next, we studied the interaction between PEGylated membranes and p-THPP. Our MD simulation results indicated that the arrangement of p-THPP within zwitterionic membranes is dependent on their free volume, and p-THPP solubilized in PEGylated liposomes is localized in two preferred positions: deep within the membrane (close to the center of the bilayer) and in the outer PEG corona (p-THPP molecules being wrapped with the polymer chains). Fluorescence quenching methods confirmed the results of atomistic MD simulations and showed two populations of p-THPP molecules as in MD simulations. Our results provide both an explanation for the experimental observation that PEGylation improves the drug-loading efficiency of membranes and also a more detailed molecular-level description of the interactions between porphyrins and lipid membranes.", author = "Monika Dzieciuch and Sami Rissanen and Natalia Szydłowska and Alex Bunker and Marta Kumorek and Dorota Jamr{\'o}z and Ilpo Vattulainen and Maria Nowakowska and Tomasz R{\'o}g and Mariusz Kepczynski", year = "2015", month = "6", day = "4", doi = "10.1021/acs.jpcb.5b01351", language = "English", volume = "119", pages = "6646--6657", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "22", }
@article{4324c6cb70fc436e9583b01cfdb604d3, title = "Equipment for obtaining polimeric nanofibres by electrospinning technology: II. The obtaining of polimeric nanofibers", abstract = "The computerized technologies and equipment for obtaining nanofibers impose high training, a large interdisciplinary substantiation, capacity for data storage, memorizing, easy usage, selectivity, fiability, stability, reduced time for analizing/processing of the technological parameters. That is why the computerized electrospinning equipment and technologies for obtaining nanofibers are possible candidates to carry out these requirements owing to the fact that they present both the proper selectivity/sensibility and the increased processing/determining/intervening speed by using the computerized control. This paper aims to present the operation and aplication of equipment for obtaining polimeric nanofibers by electrospinning technology. The designing and accomplishing of the suggested electrospinning equipment has been aimed to obtain a modular system which should allow the control of the technological parameters by means of the computer. Thus, the multitude of the parameters which influence the process of electrospinning, can be independently and automatically varied. The obtained nanofibers were studied by scanning electron microscope.", keywords = "Electrospinning, Equipment, Modular conception, Nanofibers, Technology", author = "Manea, {Liliana Rozemarie} and Bogdan Cramariuc and Vasilica Popescu and Radu Cramariuc and Ion Sandu and Oana Cramariuc", note = "EXT={"}Cramariuc, Bogdan{"}", year = "2015", month = "6", day = "1", language = "English", volume = "52", pages = "180--185", journal = "Materiale Plastice", issn = "0025-5289", publisher = "Syscom 18 SRL", number = "2", }
@article{0243beb9fa474c81b9042f19f5c64bbd, title = "Hydration of hydroxyl and amino groups examined by molecular dynamics and neutron scattering", abstract = "Neutron diffraction with isotopic substitution was performed on aqueous solutions of isopropyl alcohol and isopropylamine. The difference between these two measurements primarily contains information about the different hydration of the alcohol and amino group. This data is used as a test of the accuracy of molecular dynamic simulations of the same systems. Having established the level of accuracy of the modeling, it is employed as an interpretive tool for the experimental data. Even though the alcohol and the amine possess comparable hydrogen bonding capabilities, consisting respectively of either two hydrogen bond acceptors and one donor, or two hydrogen bond donors and one acceptor, we find significant differences in the hydration of the hydroxyl and amino groups.", author = "Jana Hlad{\'i}lkov{\'a} and Fischer, {Henry E.} and Pavel Jungwirth and Mason, {Philip E.}", year = "2015", month = "5", day = "28", doi = "10.1021/jp510528u", language = "English", volume = "119", pages = "6357--6365", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "21", }
@article{49264aed694f4eaa8981d96b7e87cad3, title = "Effect of melting state on the thermal shock resistance and thermal conductivity of APS ZrO2-7.5wt.{\%} Y2O3 coatings", abstract = "The microstructures of two types of ZrO2-7.5wt.{\%} Y2O3 (YSZ) coatings fabricated by air plasma spraying (APS) but containing different amounts of columnar grains were investigated through scanning electron microscopy and electron backscatter diffraction analysis. Differences in the formation mechanisms of columnar and equiaxed grains were characterized using particles collected in a water container, from which it was found that these mechanisms are closely related to the melted state of the in-flight particles. Furthermore, it was found that the higher the columnar grain concentration of an as-sprayed coating, the higher its thermal shock resistance. This means that it is possible to improve the thermal shock resistance of APS YSZ coatings simply by introducing more columnar grains, as this increases their thermal conductivity. Using this knowledge, YSZ coatings with good thermal shock resistance and a thermal conductivity of 0.81W·(m·K)-1 at 1100°C were successfully prepared.", keywords = "Air plasma spraying, Columnar grains, Thermal conductivity, Thermal shock resistance, YSZ coatings", author = "Xuemei Song and Ziwei Liu and Tomi Suhonen and Tommi Varis and Liping Huang and Xuebin Zheng and Yi Zeng", year = "2015", month = "5", day = "25", doi = "10.1016/j.surfcoat.2015.03.011", language = "English", volume = "270", pages = "132--138", journal = "Surface & Coatings Technology", issn = "0257-8972", publisher = "Elsevier", }
@article{a4b1734bbb9240829009277102ae213e, title = "Erosive wear of various stainless steel grades used as impeller blade materials in high temperature aqueous slurry", abstract = "Two austenitic stainless steel grades, 316L and 904L, and three duplex stainless steel grades, LDX 2101, 2205, and 2507, were erosion tested as impeller blade materials for hydrometallurgical applications. Samples were attached to the pressure and suction sides of an impeller and were tested for 72. h at 80. °C and 95. °C in a small-scale reactor using quartz sand slurry. Based on the mass losses measured, the steel grades could be ranked into two distinct categories; LDX 2101 and 2507 comprising the category with the better erosion resistance. The categories were the same for the pressure and suction side tests even though the erosion mechanism differed. In most cases, erosion was more severe in the suction side samples, which has practical implications for wear protection design. In the pressure side samples, the variation in the erosion mass loss with different experimental parameters was in line with earlier reported findings. In contrast, in the suction side samples, under some experimental conditions, increasing tip speed and increasing particle size were found to reduce erosion mass loss. This emphasizes the fact that the erosivity of particles for the impeller suction side cannot be deduced solely based on particle size. The reasons for the observed behavior are discussed.", keywords = "Erosion, Impellers, Mixing, Slurry, Stainless steels, Wear", author = "M. Lindgren and R. Suihkonen and J. Vuorinen", note = "EXT={"}Lindgren, M.{"}", year = "2015", month = "4", day = "5", doi = "10.1016/j.wear.2015.03.014", language = "English", volume = "328-329", pages = "391--400", journal = "Wear", issn = "0043-1648", publisher = "Elsevier", }
@article{2db14a0397944fa6964a431b6d9b91e2, title = "The effect of impact conditions on the wear and deformation behavior of wear resistant steels", abstract = "The deformation and wear behavior of four high strength wear resistant steels were studied in various impact conditions to evaluate their performance in applications involving heavy impacts and impact-abrasion. In the normal direction impacts, the studies were conducted with single and repeated (multiple) drop tests. To better simulate the actual application conditions, the samples were positioned at an angle relative to the impact direction in the tests with the high velocity particle impactor (HVPI) device. The effect of strain rate was investigated using constant size projectiles made from materials with different density but keeping the impact energy constant by varying the incident projectile velocity. The effect of surface hardening on the wear resistance of the high strength steels was determined by impacting the same surface area multiple times at a constant velocity using spherical high velocity projectiles. Regardless of the rather similar hardness of the studied three martensitic steel grades, the impact behavior showed differences in wear rate and damage mechanisms in each case due to the microstructural characteristics of the materials. The adiabatic shear bands forming in the martensitic steels at higher loading rates were found to increase the wear rate. Moreover, the carbide reinforced steel performed in general better than the martensitic grades but showed more brittle behavior and generation of crack networks that can affect the wear performance of the material.", keywords = "Adiabatic shear bands (ASB), High strength steel, High velocity impact, Wear testing", author = "Matti Lindroos and Vilma Ratia and Marian Apostol and Kati Valtonen and Anssi Laukkanen and Wolfgang Molnar and Kenneth Holmberg and Kuokkala, {Veli Tapani}", year = "2015", month = "4", day = "5", doi = "10.1016/j.wear.2015.02.032", language = "English", volume = "328-329", pages = "197--205", journal = "Wear", issn = "0043-1648", publisher = "Elsevier", }
@article{05b2b330b53c4835948cdf84abb06371, title = "Oxidation of cholesterol does not alter significantly its uptake into high-density lipoprotein particles", abstract = "Using replica exchange umbrella sampling we calculated free energy profiles for uptake of cholesterol and one of its oxysterols (7-ketocholesterol) from an aqueous solution into a high-density lipoprotein particle. These atomistic molecular dynamics simulations show that both sterols are readily taken up from the aqueous solution with comparable free energy minima at the surface of the particle of-17 kcal/mol for cholesterol and-14 kcal/mol for 7-ketocholesterol. Moreover, given its preferred position at the particle surface, 7-ketocholesterol is expected to be able to participate directly in biological signaling processes.", author = "Topi Karilainen and Štěp{\'a}n Timr and Ilpo Vattulainen and Pavel Jungwirth", year = "2015", month = "4", day = "2", doi = "10.1021/acs.jpcb.5b00240", language = "English", volume = "119", pages = "4594--4600", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "13", }
@article{a3a0b399c4f446c58f1ad7c3e3a24fed, title = "Effect of rheological properties of dissolved cellulose/microfibrillated cellulose blend suspensions on film forming", abstract = "Enzymatically treated cellulose was dissolved in a NaOH/ZnO solvent system and mixed together with microfibrillated cellulose (MFC) in order to find the threshold in which MFC fibers form a percolation network within the dissolved cellulose solution and in order to improve the properties of regenerated cellulose films. In the aqueous state, correlations between the rheological properties of dissolved cellulose/MFC blend suspensions and MFC fiber concentrations were investigated and rationalized. In addition, rheological properties of diluted MFC suspensions were characterized and a correlation with NaOH concentration was found, thus partly explaining the flow properties of dissolved cellulose/MFC blend suspensions. Finally, based on results from Dynamic Mechanical Analysis (DMA), MFC addition had strengthening/plasticizing effect on regenerated cellulose films if low concentrations of MFC, below the percolation threshold (5.5-6 wt{\%}, corresponding to 0.16-0.18 wt{\%} of MFC in the blend suspensions), were used.", keywords = "Blend, Dissolved cellulose, Microfibrillated cellulose, Rheology, Suspension", author = "Eve Saarikoski and Marja Rissanen and Jukka Sepp{\"a}l{\"a}", year = "2015", month = "3", day = "30", doi = "10.1016/j.carbpol.2014.11.033", language = "English", volume = "119", pages = "62--70", journal = "Carbohydrate Polymers", issn = "0144-8617", publisher = "Elsevier", }
@article{a0e7ee4f812d48b5adcda3988f898f18, title = "Corrosion mechanisms of sintered Nd-Fe-B magnets in the presence of water as vapour, pressurised vapour and liquid", abstract = "Corrosion behaviour of three commercial sintered Nd-Fe-B magnets exposed to environments containing water as vapour, pressurised vapour, and liquid was investigated in order to understand their overall corrosion performance under a range of conditions. Two types of heat humidity exposure tests, namely the 85/85 and pressure cooker test, and the immersion test combined with electrochemical measurements were used as corrosion tests. It was observed that varying the temperature, pressure, and the prevailing state of water in the exposure tests, different corrosion mechanisms were detected on the surface of Nd-Fe-B magnets. The surface finish of the magnet had an effect on the initiation of corrosion in mild heat-humidity exposure. Immersion in liquid water resulted in a corrosion topography where the Nd-rich grain-boundary phase did not corrode selectively as in the other accelerated corrosion tests but was retained intact while the matrix phase underwent corrosion. These results and the dominant corrosion mechanisms of sintered Nd-Fe-B magnets in different environments are presented and discussed in this paper.", keywords = "Corrosion, Electrochemical impedance spectroscopy, Permanent magnets, Rare-earth alloys and compounds, Scanning electron microscopy, SEM", author = "E. Isotahdon and E. Huttunen-Saarivirta and S. Heinonen and Kuokkala, {V. T.} and M. Paju", year = "2015", month = "3", day = "25", doi = "10.1016/j.jallcom.2014.12.048", language = "English", volume = "626", pages = "349--359", journal = "Journal of Alloys and Compounds", issn = "0925-8388", publisher = "Elsevier", }
@article{c906333f347249b9827cce867873f601, title = "High temperature corrosion of thermally sprayed NiCr and FeCr coatings covered with a KCl-K2SO4 salt mixture", abstract = "Current boiler tube materials and designs are sensitive to changes in process conditions. The desire to increase efficiency through the increase in process temperature and the use of high-chlorine and alkali containing fuels such as biomass is challenging. The alloying of steel to increase the corrosion resistance leads to a significant increase in cost. Thermally sprayed coatings offer promising, effective, flexible and cost efficient solution to fulfil the material needs for the future. However, some heat exchanger design alterations have to be overcome before global commercialization. High temperature corrosion in combustion plants can occur by a variety of mechanisms, including passive scale degradation with subsequent rapid scaling, loss of adhesion and scale detachment, attack by molten or partly molten deposits via fluxing reactions and intergranular/interlamellar corrosion. The activated chlorine corrosion mechanism plays a key role in the thermally sprayed coatings due to their unique lamellar structure.In this study, the corrosion behaviour of NiCr and FeCr (HVOF and wire arc) thermally sprayed coatings was tested under simplified biomass combustion conditions. The tests were carried out by using a KCl-K2SO4 salt mixture as a synthetic biomass ash, which was placed on the coated materials and then heat treated for one week (168h) at two different temperatures (550°C and 600°C) and in two different gas atmospheres (air and air+30{\%} H2O). After exposure, the metallographic cross sections of the coatings were studied with SEM/EDX. The results showed that the coatings behaved relatively well at the lower test temperature while critical interlamellar corrosion was observed in some cases at the higher test temperature. A few coatings (HVOF Ni49Cr, HVOF Ni21Cr, and wire arc sprayed Fe30Cr) showed promising performance even at 600°C in both atmospheres (dry and wet).", keywords = "Biomass, Corrosion protection, High temperature corrosion, HVOF, Thermal spray coating, Wire arc", author = "T. Varis and D. Bankiewicz and P. Yrjas and M. Oksa and T. Suhonen and S. Tuurna and K. Ruusuvuori and S. Holmstr{\"o}m", year = "2015", month = "3", day = "15", doi = "10.1016/j.surfcoat.2014.11.012", language = "English", volume = "265", pages = "235--243", journal = "Surface & Coatings Technology", issn = "0257-8972", publisher = "Elsevier", }
@article{16e9dabfe9da40c39038a5dd9a08a417, title = "Tribology of HVOF- and HVAF-sprayed WC-10Co4Cr hardmetal coatings: A comparative assessment", abstract = "This paper provides a comprehensive assessment of the sliding and abrasive wear behaviour of WC-10Co4Cr hardmetal coatings, representative of the existing state-of-the-art. A commercial feedstock powder with two different particle size distributions was sprayed onto carbon steel substrates using two HVOF and two HVAF spray processes. Mild wear rates of <10-7mm3/(Nm) and friction coefficients of ≈0.5 were obtained for all samples in ball-on-disk sliding wear tests at room temperature against Al2O3 counterparts. WC-10Co4Cr coatings definitely outperform a reference electrolytic hard chromium coating under these test conditions. Their wear mechanisms include extrusion and removal of the binder matrix, with the formation of a wavy surface morphology, and brittle cracking. The balance of such phenomena is closely related to intra-lamellar features, and rather independent of those properties (e.g. indentation fracture toughness, elastic modulus) which mainly reflect large-scale inter-lamellar cohesion, as quantitatively confirmed by a principal component analysis. Intra-lamellar dissolution of WC into the matrix indeed increases the incidence of brittle cracking, resulting in slightly higher wear rates. At 400°C, some of the hardmetal coatings fail because of the superposition between tensile residual stresses and thermal expansion mismatch stresses (due to the difference between the thermal expansion coefficients of the steel substrate and of the hardmetal coating). Those which do not fail, on account of lower residual stresses, exhibit higher wear rates than at room temperature, due to oxidation of the WC grains.The resistance of the coatings against abrasive wear, assessed by dry sand-rubber wheel testing, is related to inter-lamellar cohesion, as proven by a principal component analysis of the collected dataset. Therefore, coatings deposited from coarse feedstock powders suffer higher wear loss than those obtained from fine powders, as brittle inter-lamellar detachment is caused by their weaker interparticle cohesion, witnessed by their systematically lower fracture toughness as well.", keywords = "Abrasive wear, Hardmetal, High velocity air-fuel (HVAF), High velocity oxy-fuel (HVOF), Sliding wear, WC-10Co4Cr", author = "G. Bolelli and Berger, {L. M.} and T. B{\"o}rner and H. Koivuluoto and L. Lusvarghi and C. Lyphout and N. Markocsan and V. Matikainen and P. Nyl{\'e}n and P. Sassatelli and R. Trache and P. Vuoristo", year = "2015", month = "3", day = "15", doi = "10.1016/j.surfcoat.2015.01.048", language = "English", volume = "265", pages = "125--144", journal = "Surface & Coatings Technology", issn = "0257-8972", publisher = "Elsevier", }
@article{95b0220d241949e9a98ee85761922722, title = "Exploring the role of stearic acid in modified zinc aluminum layered double hydroxides and their acrylonitrile butadiene rubber nanocomposites", abstract = "The proposed study attempted to explore the role of stearic acid modification on the properties of zinc-aluminum based layered double hydroxides (LDH) and their composites with acrylonitrile butadiene rubber (NBR). Three distinctive LDH systems were adapted for such comparison; an unmodified LDH and two stearic acid modified LDH. The use of zinc oxide and stearic acid in the rubber formulation was avoided as the modified LDH would be able to deliver the necessary activators for the vulcanization process. Emphasis was predominantly given to reconnoiter the merits of stearic acid modification on the increase in interlayer distance of the LDH. X-ray diffraction studies and transmission electron microscope morphological investigations of LDH powders indicated that modification with stearic acid increased the interlayer spacing which would favor the intercalation of NBR polymer chains into the layered space. However, stress-strain studies indicated better mechanical properties for composites with unmodified LDH. Composites with LDH showed higher crosslinking densities than conventionally sulfur cured control compounds using zinc oxide/stearic acid as activators. This was evident from equilibrium swelling method as well as statistical theory of rubber elasticity.", keywords = "crosslinking, elastomers, mechanical properties, properties and characterization, rubber", author = "Eshwaran, {Subramani Bhagavatheswaran} and Debdipta Basu and Vaikuntam, {Sankar Raman} and Burak Kutlu and Sven Wiessner and Amit Das and Kinsuk Naskar and Gert Heinrich", year = "2015", month = "3", day = "1", doi = "10.1002/app.41539", language = "English", volume = "132", journal = "Journal of Applied Polymer Science", issn = "0021-8995", publisher = "Wiley", number = "9", }
@article{2b5ce3d1c9ca4792a70f104656897059, title = "Polymer looping is controlled by macromolecular crowding, spatial confinement, and chain stiffness", abstract = "We study by extensive computer simulations the looping characteristics of linear polymers with varying persistence length inside a spherical cavity in the presence of macromolecular crowding. For stiff chains, the looping probability and looping time reveal wildly oscillating patterns as functions of the chain length. The effects of crowding differ dramatically for flexible versus stiff polymers. While for flexible chains the looping kinetics is slowed down by the crowders, for stiffer chains the kinetics turns out to be either decreased or facilitated, depending on the polymer length. For severe confinement, the looping kinetics may become strongly facilitated by crowding. Our findings are of broad impact for DNA looping in the crowded and compartmentalized interior of living biological cells.", author = "Jaeoh Shin and Cherstvy, {Andrey G.} and Ralf Metzler", year = "2015", month = "2", day = "17", doi = "10.1021/mz500709w", language = "English", volume = "4", pages = "202--206", journal = "ACS Macro Letters", issn = "2161-1653", publisher = "American Chemical Society ACS", number = "2", }
@article{c73c087807314e0f80a837c8d0cc387d, title = "Sulfonated polyetheretherketone/polypropylene polymer blends for the production of photoactive materials", abstract = "Sulfonated polyetheretherketone (SPEEK) was synthesized via a mono-substitution reaction of PEEK in concentrated sulphuric acid and was blended with polypropylene (PP) in 2-10{\%}w/w concentration to be used for the production of photoactive thermoplastic products. SPEEK and SPEEK/PP blends were characterized using FTIR, DSC, TGA, NMR, rheology, SEM, and EPR. Under UV-Vis irradiation, stable benzophenone ketyl (BPK) radicals were generated by hydrogen extraction from PP. By increasing the amount of SPEEK in the polymer blend a linear increase in the BPK radicals was achieved according to the EPR data. DSC and TGA tests indicated weaknesses in the thermal stability of SPEEK but according to the rheological tests this should not have a major effect on processabililty. The optimal amount of SPEEK in the blend was obtained at 5{\%}w/w. This concentration provided a good compromise between radical concentration, material processability, and cost.", keywords = "Blends, Photochemistry, Polyolefins", author = "Enrico Fatarelle and Ville Myll{\"a}ri and Marco Ruzzante and Rebecca Pogni and Baratto, {Maria Camilla} and Mikael Skrifvars and Seppo Syrj{\"a}l{\"a} and Pentti J{\"a}rvel{\"a}", note = "Article first published online: 1 OCT 2014 ;(Volume 132, Issue 8, February 20, 2015)Contribution: organisation=mol,FACT1=1Portfolio EDEND: 2014-12-30Publisher name: JohnWiley & Sons, Inc.", year = "2015", month = "2", day = "1", doi = "10.1002/app.41509", language = "English", volume = "132", journal = "Journal of Applied Polymer Science", issn = "0021-8995", publisher = "Wiley", number = "8", }
@article{265d8ee5ec65401f883f673ea242bf79, title = "Supramolecular hierarchy among halogen and hydrogen bond donors in light-induced surface patterning", abstract = "Halogen bonding, a noncovalent interaction possessing several unique features compared to the more familiar hydrogen bonding, is emerging as a powerful tool in functional materials design. Herein, we unambiguously show that one of these characteristic features, namely high directionality, renders halogen bonding the interaction of choice when developing azobenzene-containing supramolecular polymers for light-induced surface patterning. The study is conducted by using an extensive library of azobenzene molecules that differ only in terms of the bond-donor unit. We introduce a new tetrafluorophenol-containing azobenzene photoswitch capable of forming strong hydrogen bonds, and show that an iodoethynyl-containing azobenzene comes out on top of the supramolecular hierarchy to provide unprecedented photoinduced surface patterning efficiency. Specifically, the iodoethynyl motif seems highly promising in future development of polymeric optical and photoactive materials driven by halogen bonding.", author = "Marco Saccone and Valentina Dichiarante and Alessandra Forni and Alexis Goulet-Hanssens and Gabriella Cavallo and Jaana Vapaavuori and Giancarlo Terraneo and Barrett, {Christopher J.} and Giuseppe Resnati and Pierangelo Metrangolo and Arri Priim{\"a}gi", note = "EXT={"}Saccone, Marco{"} EXT={"}Vapaavuori, Jaana{"}", year = "2015", month = "1", day = "28", doi = "10.1039/c4tc02315c", language = "English", volume = "3", pages = "759--768", journal = "Journal of Materials Chemistry C", issn = "2050-7526", publisher = "Royal Society of Chemistry", }
@article{6c5cba782dc64ad9a83be6889c6b02d9, title = "Are coarse-grained models apt to detect protein thermal stability? the case of OPEP force field", abstract = "We present the first investigation of the kinetic and thermodynamic stability of two homologous thermophilic and mesophilic proteins based on the coarse-grained model OPEP. The object of our investigation is a pair of G-domains of relatively large size, 200 amino acids each, with an experimental stability gap of about 40 K. The OPEP force field is able to maintain stable the fold of these relatively large proteins within the hundred-nanosecond time scale without including external constraints. This makes possible to characterize the conformational landscape of the folded protein as well as to explore the unfolding. In agreement with all-atom simulations used as a reference, we show that the conformational landscape of the thermophilic protein is characterized by a larger number of substates with slower dynamics on the network of states and more resilient to temperature increase. Moreover, we verify the stability gap between the two proteins using replica-exchange simulations and estimate a difference between the melting temperatures of about 23 K, in fair agreement with experiment. The detailed investigation of the unfolding thermodynamics allows to gain insight into the mechanism underlying the enhanced stability of the thermophile relating it to a smaller heat capacity of unfolding.", keywords = "Coarse-grained force field, Conformational substates network, Molecular dynamics, Protein thermodynamic stability, Thermophilic proteins", author = "Maria Kalimeri and Philippe Derreumaux and Fabio Sterpone", year = "2015", month = "1", day = "1", doi = "10.1016/j.jnoncrysol.2014.07.005", language = "English", volume = "407", pages = "494--501", journal = "Journal of Non-Crystalline Solids", issn = "0022-3093", publisher = "Elsevier", }
@article{a1d37a6516a3482b8f1b180620153ca3, title = "Aryl end-capped quaterthiophenes applied as anode interfacial layers in inverted organic solar cells", abstract = "Four aryl end-capped quaterthiophene derivatives were synthesized and their material properties were studied by computational, spectroscopic, electrochemical, and thermoanalytical methods. Compounds were applied as interfacial layers between the bulk heterojunction active layer and Ag anode in inverted organic solar cells. Results show that p-cyanophenyl end-capped quaterthiophene with hexyl side chains increases both the short circuit current density and power conversion efficiency notably compared to reference interlayer material, tris-(8-hydroxyquinoline)aluminum. The improved cell performance was attributed to the optimal positions of the highest occupied molecular orbital and the lowest unoccupied molecular orbital (LUMO) of this material, relative to those of the photoactive electron donor poly(3-hexylthiophene) and Ag anode, and evenly distributed LUMO. In addition, the use of these materials as an anode interfacial layer increases the absorption of the solar cell, which could contribute to the formation of excitons and additional current production by the cell.", keywords = "Anode interfacial layer, Bulk heterojunction, Computational research, Inverted organic solar cell, Oligothiophene, Spectroscopy, Suzuki-Miyaura", author = "Heiskanen, {J. P.} and Manninen, {V. M.} and D. Pankov and Omar, {W. A. E.} and T. Kastinen and Hukka, {T. I.} and Lemmetyinen, {H. J.} and Hormi, {O. E. O.}", note = "EXT={"}Heiskanen, J. P.{"}", year = "2015", month = "1", day = "1", doi = "10.1016/j.tsf.2014.12.007", language = "English", volume = "574", pages = "196--206", journal = "Thin Solid Films", issn = "0040-6090", publisher = "Elsevier", }
@article{04b02a2f5a60412ab0aca14ba07a5d3e, title = "Perfluoro-1,1′-biphenyl and perfluoronaphthalene and their derivatives as π-acceptors for anions", abstract = "Addition of anions to perfluorinated 1,1′-biphenyl 1 or naphthalene 2 results in a shift of the 19F NMR signals. However, any specific interaction cannot be assigned to this effect. In order to study the interaction in more detail, the salt derivatives 3 and 4 were prepared and studied by single crystal X-ray diffraction revealing weak anion-π interactions in the solid state.", author = "H. Yi and M. Albrecht and A. Valkonen and K. Rissanen", year = "2015", month = "1", day = "1", doi = "10.1039/c4nj01654h", language = "English", volume = "39", pages = "746--749", journal = "New Journal of Chemistry", issn = "1144-0546", publisher = "Royal Society of Chemistry", number = "1", }
@article{20d239d9153d4f1aa6ebeedfc6cf6785, title = "Dielectric Breakdown Strength of Thermally Sprayed Ceramic Coatings: Effects of Different Test Arrangements", abstract = "Dielectric properties (e.g., DC resistivity and dielectric breakdown strength) of insulating thermally sprayed ceramic coatings differ depending on the form of electrical stress, ambient conditions, and aging of the coating, however, the test arrangements may also have a remarkable effect on the properties. In this paper, the breakdown strength of high velocity oxygen fuel-sprayed alumina coating was studied using six different test arrangements at room conditions in order to study the effects of different test and electrode arrangements on the breakdown behavior. In general, it was shown that test arrangements have a considerable influence on the results. Based on the results, the recommended testing method is to use embedded electrodes between the voltage electrode and the coating at least in DC tests to ensure a good contact with the surface. With and without embedded electrodes, the DBS was 31.7 and 41.8 V/µm, respectively. Under AC excitation, a rather good contact with the sample surface is, anyhow, in most cases acquired by a rather high partial discharge activity and no embedded electrodes are necessarily needed (DBS 29.2 V/µm). However, immersion of the sample in oil should strongly be avoided because the oil penetrates quickly into the coating affecting the DBS (81.2 V/µm).", keywords = "AlO, breakdown strength, coating, dielectric, HVOF, thermal spraying", author = "Minna Niittym{\"a}ki and Kari Lahti and Tomi Suhonen and Jarkko Mets{\"a}joki", note = "EXT={"}Mets{\"a}joki, Jarkko{"}", year = "2015", doi = "10.1007/s11666-014-0211-1", language = "English", volume = "24", pages = "542--551", journal = "Journal of Thermal Spray Technology", issn = "1059-9630", publisher = "ASM International", number = "3", }
@article{33521ac65d8c44aaae9bc9a5c378f281, title = "Influence of the Spray Gun Type on Microstructure and Properties of HVAF Sprayed Fe-Based Corrosion Resistant Coatings", abstract = "The aim of this study is to evaluate the microstructural details and corrosion properties of novel Fe-based coatings prepared using two different generations of HVAF spray guns. These two generations of HVAF guns are Activated Combustion HVAF (AC-HVAF, 2nd generation) M2 gun and Supersonic Air Fuel HVAF (SAF, 3rd generation) M3 gun. Structural details were analysed using x-ray diffractometry and field-emission scanning electron microscope. Higher denseness with homogeneous microstructure was achieved for Fe-based coating deposited by the M3 process. Such coatings exhibit higher particle deformation and lower oxide content compared to coatings manufactured with M2 gun. Corrosion properties were studied by open-cell potential measurements and electrochemical impedance spectroscopy. The lower porosity and higher interlamellar cohesion of coating manufactured with M3 gun prevent the electrolyte from penetrating through the coating and arriving to the substrate, enhancing the overall corrosion resistance. This can be explained by the improved microstructures and coating performance.", keywords = "corrosion behavior, Fe-based coatings, HVAF, structure", author = "A. Milanti and H. Koivuluoto and P. Vuoristo", year = "2015", doi = "10.1007/s11666-015-0298-z", language = "English", volume = "24", pages = "1312--1322", journal = "Journal of Thermal Spray Technology", issn = "1059-9630", publisher = "ASM International", number = "7", }
@article{a1a54d7003624c4c9f2285c87177b59d, title = "Mechanical performance and CO2 uptake of ion-exchanged zeolite A structured by freeze-casting", abstract = "Zeolite 4A has been freeze-cast into highly porous monoliths with a cylindrical shape. The brittle monoliths, with lamellar or columnar pores and wall thicknesses between 8 and 35μm, show a compressive mechanical response along the main pore axis that could be modeled by a buckling behavior. The failure strength is proportional to the density and the amount of transverse bridging across lamella, which was shown to be related to the pore cross-sectional aspect ratio. Monoliths with highly anisotropic pores with a cross-sectional aspect ratio higher than 3 yielded sequentially from the top surface, whereas monoliths with a pore aspect ratio lower than 3 were found to delaminate into longitudinal splinters. The freeze-cast monoliths show a sharp gas breakthrough front with a 1:9 mixture of CO2 and N2, indicating rapid uptake kinetics of the lamellar structures.", keywords = "Freeze-casting, Laminate, Mechanical strength, Porous ceramics, Zeolite A", author = "Arto Ojuva and Matti J{\"a}rvel{\"a}inen and Marcus Bauer and Lassi Keskinen and Masi Valkonen and Farid Akhtar and Erkki Lev{\"a}nen and Lennart Bergstr{\"o}m", note = "ORG=mol,0.5 ORG=sgn,0.5", year = "2015", doi = "10.1016/j.jeurceramsoc.2015.03.001", language = "English", volume = "35", pages = "2607--2618", journal = "Journal of the European Ceramic Society", issn = "0955-2219", publisher = "Elsevier", number = "9", }
@article{2d7989a40fff48049a343b7a7b8015a2, title = "Stimuli-responsive photonic polymer coatings", abstract = "This feature article focuses on the highlights in the development of photonic polymer coatings that can change their volume or surface topology in a reversible, dynamic fashion when exposed to an external stimulus. Topographic response is established using hydrogels or liquid crystal polymer networks. By changing the surface corrugation in response to light various functional coating properties can be modulated, for instance wettability and/or mechanical friction. The same volume changes in photonic coatings caused by different stimuli lead to changes in light reflection.", author = "Stumpel, {Jelle E.} and Broer, {Dirk J.} and Schenning, {Albertus P H J}", note = "EXT={"}Stumpel, Jelle{"}", year = "2014", month = "12", day = "28", doi = "10.1039/c4cc05072j", language = "English", volume = "50", pages = "15839--15848", journal = "Chemical Communications", issn = "1359-7345", publisher = "ROYAL SOC CHEMISTRY", number = "100", }
@article{80d472e5d5d949c6b2860e31be9f0986, title = "DNA lesion can facilitate base ionization: Vertical ionization energies of aqueous 8-oxoguanine and its nucleoside and nucleotide", abstract = "8-Oxoguanine is one of the key products of indirect radiation damage to DNA by reactive oxygen species. Here, we describe ionization of this damaged nucleobase and the corresponding nucleoside and nucleotide in aqueous phase, modeled by the nonequilibrium polarizable continuum model, establishing their lowest vertical ionization energies of 6.8-7.0 eV. We thus confirm that 8-oxoguanine has even lower ionization energy than the parental guanine, which is the canonical nucleobase with the lowest ionization energy. Therefore, it can act as a trap for the cationic hole formed by ionizing radiation and thus protect DNA from further radiation damage. We also model using time-dependent density functional theory and measure by liquid jet photoelectron spectroscopy the valence photoelectron spectrum of 8-oxoguanine in water. We show that the calculated higher lying ionization states match well the experiment which, however, is not sensitive enough to capture the electron signal corresponding to the lowest ionization process due to the low solubility of 8-oxoguanine in water.", author = "Vladim{\'i}r Palivec and Eva Pluharov{\'a} and Isaak Unger and Bernd Winter and Pavel Jungwirth", year = "2014", month = "12", day = "4", doi = "10.1021/jp5111086", language = "English", volume = "118", pages = "13833--13837", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "48", }
@article{743450072e7f4e0683fae4c1f214887f, title = "Unmodified LDH as reinforcing filler for XNBR and the development of flame-retardant elastomer composites", abstract = "Layered double hydroxides (LDHs), inorganic clay materials with mixed metals present in the structure along with some interlayer cations, have immense potential for use as a filler in rubbers.Wereport the preparation and properties of a set of novel nanocomposites consisting of aLDHdispersed in carboxylic-acrylonitrile-butadiene rubber (XNBR).Wesucceed in obtaining significantly improved physical properties by altering the chemical structure of a LDH with Zn and Al ions (Zn-Al LDH). In particular, we discover a significant reinforcing effect. This occurs despite the size difference between the LDH and traditional reinforcing fillers such as precipitated silica and carbon black. Both the elastic modulus and tensile strength increase. This increase is a function of the LDH concentration and, reaches a maximum value when the LDH concentration is at 100 phr. Experimental evidence suggests that this reinforcing effect is due to direct ion-to-ion interaction between the filler and the matrix. In addition, we report that the presence of the nanofiller positively affects the flame retardence and thermal decomposition of the nanocomposites. We attribute this effect to the presence of a layer formed by the nanofiller.", author = "Debdipta Basu and Amit Das and Jinu Jacobgeorge and Wang, {De Yi} and Klauswerner St{\"o}ckelhuber and Udo Wagenknecht and Andreas Leuteritz and Burak Kutlu and Uta Reuter and Gert Heinrich", year = "2014", month = "12", day = "1", doi = "10.5254/rct.14.86920", language = "English", volume = "87", pages = "606--616", journal = "Rubber Chemistry and Technology", issn = "0035-9475", publisher = "Rubber Division of the American Chemical Society", number = "4", }
@article{015005182bc64903826bce7863d6dffe, title = "Fabrication and Characterization of Amorphous Alumina-Yttria-Stabilized Zirconia Coatings by Air Plasma Spraying", abstract = "Almost fully amorphous coatings of near-eutectic alumina-yttria-stabilized zirconia (Al2O3-YSZ) were prepared by air plasma spraying using Al2O3and 8 mol.{\%} YSZ crystalline-mixed powders. The coatings consist of mostly an amorphous phase with a small amount of nanocrystals. Various characterization techniques were used to understand coating formation and the origins of the different phases within the coatings. The formation of the mostly amorphous structure is attributed to the high glass-forming ability of Al2O3-YSZ and the appropriate plasma spraying conditions. A small number of nanocrystals are produced during crystallization of the incoming molten droplets or by recrystallization of the solidified splats by accumulated heat. Scanning electron microscopy shows that the coatings have a dense, layered structure with low porosity, and bright-field transmission electron microscopy images indicate sharp interface rather than grit-blasted wavy surface between splats and substrates in the coatings. The as-sprayed amorphous coatings crystallized at around 920 °C and micro-hardness of the as-sprayed amorphous coatings was 8.12 GPa.", keywords = "alumina-yttria-stabilized zirconia, amorphous phases, atmospheric plasma spraying, micro-hardness, nanocrystals, thermal stability", author = "Xuemei Song and Tomi Suhonen and Tommi Varis and Liping Huang and Xuebin Zheng and Yi Zeng", year = "2014", month = "11", day = "25", doi = "10.1007/s11666-014-0124-z", language = "English", volume = "23", pages = "1302--1311", journal = "Journal of Thermal Spray Technology", issn = "1059-9630", publisher = "ASM International", number = "8", }
@article{46d6e8d689714223865c6aef50005425, title = "Processable aromatic polyesters based on bisphenol derived from cashew nut shell liquid: synthesis and characterization", abstract = "A new bisphenol viz., 4-(4-hydroxyphenoxy)-3-pentadecylphenol (HPPDP) was synthesized starting from cashew nut shell liquid (CNSL). Aromatic (co)polyesters containing ether linkages in the main chain and pendent pentadecyl chains were synthesized by the interfacial polycondensation of HPPDP with terephthalic acid chloride (TPC), isophthalic acid chloride (IPC) and a mixture of TPC and IPC (50:50 mol {\%}) and by polycondenation of varying composition of HPPDP and bisphenol-A (BPA) with TPC. The resultant (co)polyesters exhibited inherent viscosities in the range 0.70–1.21 dL g−1 and number-average molecular weights in the range 16,000–48,200 (GPC, polystyrene standard). Polyesters were soluble in common organic solvents such as chloroform and dichloromethane and could be cast into films from chloroform solution. Polyesters exhibited T10 values in the range 430–455 °C and Tg values were in the range 29–202 °C. Dynamic mechanical storage modulus and maximum on transition of tan δ curve decreased with increased content of HPPDP in copolyesters. Importantly, the large difference between Tg and T10 values offers the possibility to process these polyesters in the melt.", keywords = "Aromatic polyesters, Cashew nut shell liquid, Pentadecyl, Polycondensation, Processability, Thermal properties", author = "Tawade, {Bhausaheb V.} and Salunke, {Jagadish K.} and Sane, {Prakash S.} and Wadgaonkar, {Prakash P.}", note = "EXT=”Salunke, Jagadish”", year = "2014", month = "11", day = "18", doi = "10.1007/s10965-014-0617-y", language = "English", volume = "21", journal = "JOURNAL OF POLYMER RESEARCH", issn = "1022-9760", publisher = "Springer Verlag", number = "12", }
@article{019f5eec7ba84e5480442692e603d7d0, title = "Electromagnetic interference shielding effectiveness of MWCNT filled poly(ether sulfone) and poly(ether imide) nanocomposites", abstract = "Multiwalled carbon nanotube (MWCNT) filled poly(ether sulfone) (PES) and poly(ether imide) (PEI) composites were prepared with different MWCNT weight fractions (0.5-5wt{\%}) by a solution mixing technique. Their electrical conductivities, electromagnetic interference (EMI), shielding effectiveness (SE), return loss (RL), and absorption loss (AL) were investigated. Morphologies of the fracture surfaces of nanocomposites studied by scanning electron and transmission electron microscopy showed relatively good MWCNT dispersion and distribution. The electrical conductivity of compression molded samples measured at room temperature indicated that the electrical percolation network was achieved already at 0.5{\%} loading. The measurements of shielding effectiveness (SE) carried out in the frequency range of 8 to 12 GHz (X-band range) showed that SE increases with measurement frequency and with filler loading, whereby no significant differences could be observed between PES and PEI as matrices. The nanocomposites based on both matrices with 5 wt{\%} loading of MWCNT exhibited shielding levels at 8 GHz between 42 and 45 dB in comparison with the pure polymers which showed value in the range of 1 to 2 dB. RL and AL showed significantly lower values for the composites as compared to unfilled polymers, but no systematic trends were observed on frequency.", author = "Mohanty, {Aruna Kumar} and Anindita Ghosh and Pravin Sawai and Kapil Pareek and Susanta Banerjee and Amit Das and Petra P{\"o}tschke and Gert Heinrich and Brigitte Voit", year = "2014", month = "11", day = "1", doi = "10.1002/pen.23804", language = "English", volume = "54", pages = "2560--2570", journal = "Polymer Engineering and Science", issn = "0032-3888", publisher = "Wiley", number = "11", }
@article{44f3f0f8d1d34d17829e459730e4e020, title = "A supramolecular approach to photoresponsive thermo/solvoplastic block copolymer elastomers", abstract = "With the aim of preparing supramolecular photoresponsive block copolymer elastomers, a series of ABA triblock copolymers with a poly(n-butyl acrylate) (PnBA) middle block and poly(dimethylaminoethyl methacrylate) (PDMAEMA or PDM) outer blocks were synthesized by atom transfer radical polymerization (ATRP), followed by PDM quaternization (giving PDMQ-PnBA-PDMQ) and then by ionic complexation with methyl orange (MO), an azo-containing and sulfonate-functionalized commercially available compound (giving PDMQ/MO-PnBA-PDMQ/MO). The PnBA block, which has a subambient glass transition, and the quaternized and complexed blocks, which have high glass transitions, form phase-separated soft and hard blocks, respectively. Simple elasticity tests of solvent-cast films show that the PDMQ/MO-PnBA-PDMQ/MO with hard block content between 18 and 29 wt {\%} (as well as PDMQ-PnBA-PDMQ with 18 wt {\%} hard block content) have significant elastomeric character. AFM and TEM (atomic force and transmission electron microscopies) of spin-coated films show a correlation between the elastomeric character and morphologies where the hard block forms a dispersed minority phase (spherical and/or short cylindrical domains). A continuous hard phase is observed for a hard block content of around 37 wt {\%}; these materials show no significant elasticity. Reversible photoisomerization, with relatively high cis isomer content in the photostationary state, was also demonstrated.", author = "Xin Wang and Jaana Vapaavuori and Yue Zhao and Bazuin, {C. Geraldine}", year = "2014", month = "10", day = "28", doi = "10.1021/ma501278b", language = "English", volume = "47", pages = "7099--7108", journal = "Macromolecules", issn = "0024-9297", publisher = "American Chemical Society", number = "20", }
@article{c98ceb7ede594fb895fb18af0fe5d6c0, title = "Rapid, Brushless Self-assembly of a PS-b-PDMS Block Copolymer for Nanolithography", abstract = "Block copolymers (BCP) are highly promising self-assembling precursors for scalable nanolithography. Very regular BCP nanopatterns can be used as on-chip etch masks. The first step in the processing of BCP thin films is usually the chemical modification of the substrate surface, typically by grafting of a brush layer that renders the surface energy neutral relative to the constituent blocks. We provide here a first study on rapid, low temperature self-assembly of PS-. b-PDMS (polystyrene-. block-polydimethylsiloxane) on silicon substrates without a brush layer. We show that it forms line and antidot patterns after short solvo-thermal annealing. Unlike previous reports on this system, low temperature and short annealing time provide self-assembly in homogeneous thin films covering large substrate areas. This on-chip mask was then used for pattern transfer to the underlying silicon substrate. SEM (scanning electron microscope) images reveal silicon nanowires relative to the PDMS patterns of the BCP mask.", keywords = "Aspect ratio, Brushless, Dry etching, Lines and antidots, Pattern transfer, PS-b-PDMS, Self-assembly, Silicon nanostructures, Soft mask template, Solvo-thermal annealing", author = "Sozaraj Rasappa and Lars Schulte and Dipu Borah and Morris, {Michael A.} and Sokol Ndoni", year = "2014", month = "10", day = "1", doi = "10.1016/j.colcom.2014.07.001", language = "English", volume = "2", pages = "1--5", journal = "Colloids and Interface Science Communications", issn = "2215-0382", publisher = "Elsevier BV", }
@article{4ae5e797cb6c4813b04990bb946e8821, title = "Effect of head group size on the photoswitching applications of azobenzene Disperse Red 1 analogues", abstract = "We investigate the effect of the increased molecular bulk in the 'head' group for a class of newly synthesized azobenzene chromophores with a clickable ethynyl group para and a nitro group ortho to the azo bond on the distal benzene ring. This 'variable-head' functionalization provides a family of dyes with photophysical characteristics very similar to those of Disperse Red 1, one of the most commonly used azo dyes in materials science. Phenyl, naphthyl, and anthracyl derivatives were synthesized as small molecules, monomers, homopolymers, and copolymers in a rapid and facile manner using click chemistry, confirming the versatility of this parent chromophore. Photochemical and spectral studies indicate that this strategy is suitable to build a 'bulkiness series' of stimuli-responsive materials, as the various material derivatives retain the absorption and kinetic characteristics of the parent chromophore necessary for all optical patterning applications that DR1 dyes have been optimized for. In thin films, larger head group size was found to increase the stability of light-induced birefringence in copolymers. The homopolymers formed stable surface-relief gratings upon interference irradiation, whose grating depths correlate with head group size, demonstrating that this new class of polymers can also undergo tailored macroscopic photoinduced motions, which could have applications in all optical nano-patterning.", author = "Alexis Goulet-Hanssens and Corkery, {T. Christopher} and Arri Priimagi and Barrett, {Christopher J.}", year = "2014", month = "9", day = "28", doi = "10.1039/c4tc00996g", language = "English", volume = "2", pages = "7505--7512", journal = "Journal of Materials Chemistry C", issn = "2050-7526", publisher = "Royal Society of Chemistry", number = "36", }
@article{962515a25c304226b76db99a4156a544, title = "Recent twists in photoactuation and photoalignment control", abstract = "The design of functional and stimuli-responsive materials is among the key goals of modern materials science. The structure and properties of such materials can be controlled via various stimuli, among which light is often times the most attractive choice. Light is ubiquitous and a gentle energy source and its properties can be optimized for a specific target remotely, with high spatial and temporal resolution. Light-control over molecular alignment has in recent years attracted particular interest, for potential applications such as reconfigurable photonic elements and optical-to-mechanical energy conversion. Herein, we bring forward some recent examples and emerging trends in this exciting field of research, focusing on liquid crystals, liquid-crystalline polymers and photochromic organic crystals, which we believe serve to highlight the immense potential of light-responsive materials to a wide variety of current and future high-tech applications in photonics, energy harvesting and conversion. This journal is", author = "Arri Priimagi and Barrett, {Christopher J.} and Atsushi Shishido", year = "2014", month = "9", day = "21", doi = "10.1039/c4tc01236d", language = "English", volume = "2", pages = "7155--7162", journal = "Journal of Materials Chemistry C", issn = "2050-7526", publisher = "Royal Society of Chemistry", number = "35", }
@article{2d3a765fd4b14a7eb8ab125d7f7efa84, title = "Effects of composition and microstructure on the abrasive wear performance of quenched wear resistant steels", abstract = "Wear resistant steels are commonly categorized by their hardness, and in the case of quenched wear resistant steels, their Brinell hardness grades are widely considered almost as standards. In this study, the abrasive wear performance of 15 commercially available 400 HB grade quenched wear resistant steels from all over the world were tested with granite gravel in high stress conditions. The aim was to evaluate the real wear performance of nominally similar steels. Also properties such as hardness, hardness profiles, microstructures and chemical compositions of the steels were studied and reasons for the differences in their wear performance further discussed. In terms of mass loss, over 50{\%} differences were recorded in the abrasive wear performance of the studied steels. Variations in the chemical compositions were linked to the auto-tempered microstructures of the steels, and the microstructural characteristics were further linked to their ultimate wear behavior. {\circledC} 2014 Elsevier B.V.", keywords = "Abrasion, Hardness, Microstructure, Mineral processing, Steel, Wear testing", author = "Niko Ojala and Kati Valtonen and Vuokko Heino and Marke Kallio and Joonas Aaltonen and Pekka Siitonen and Kuokkala, {Veli Tapani}", note = "Contribution: organisation=mol,FACT1=1Portfolio EDEND: 2014-11-28Publisher name: Elsevier", year = "2014", month = "9", day = "15", doi = "10.1016/j.wear.2014.06.003", language = "English", volume = "317", pages = "225--232", journal = "Wear", issn = "0043-1648", publisher = "Elsevier", number = "1-2", }
@article{24c9fd3048b042309a95d18bc4121739, title = "Effect of silane integrated sol-gel derived in situ silica on the properties of nitrile rubber", abstract = "Nitrile rubber/silica composites are prepared by a sol-gel process using tetraethoxysilane as precursor in the presence of γ- mercaptopropyltrimethoxysilane as a silane coupling agent. Here, we follow a novel processing route where the silica particles are generated inside the rubber matrix before compounding with vulcanizing ingredients. The effect of in situ generated silanized silica on the properties of the rubber composite has been evaluated by studying curing characteristics, morphology, mechanical and dynamic mechanical properties. Enhanced rubber-filler interaction of these composites is revealed from stress-strain studies and dynamic mechanical analysis. Excessive use of silane shows an adverse effect on mechanical properties of the composites. Due to finer dispersed state of the in situ silica and enhanced rubber-filler interaction, the mechanical properties and thermal stability of the composites are improved compared to corresponding ex situ processed composite.", keywords = "elastomers, mechanical properties, morphology, rheology, structure-property relations", author = "Kapgate, {Bharat P.} and Chayan Das and Debdipta Basu and Amit Das and Gert Heinrich and Uta Reuter", year = "2014", month = "8", day = "5", doi = "10.1002/app.40531", language = "English", volume = "131", journal = "Journal of Applied Polymer Science", issn = "0021-8995", publisher = "Wiley", number = "15", }
@article{4f49a057581240ca89564be77de53bc2, title = "Performance testing of iron based thermally sprayed HVOF coatings in a biomass-fired fluidised bed boiler", abstract = "Managing high temperature corrosion problems in biomass firing boilers has been challenging especially due to high amounts of chemically active compounds, in particular alkali chlorides. Thermally sprayed coatings with high chromium content can offer a solution for protecting low alloyed substrate materials in locations prone to high temperature corrosion. Two thermally sprayed (HVOF - high velocity oxy-fuel) iron based coatings (Fe-27Cr-11Ni-4Mo and Fe-19Cr-9W-7Nb-4Mo) were exposed to biomass boiler conditions for two years. The fluidised bed boiler for district heating used mainly wood-based fuels mixed with small amounts of peat. The coated tubes were located at the hot economiser of the boiler, where the estimated material temperature was about 200. °C maximum. After the exposure the coatings and the carbon steel St35.8 substrate material were analysed with SEM-EDX. It was detected that corrosion due to elements such as chlorine, potassium, zinc, lead and copper had caused severe material wastage in the biomass boiler with relatively low heat exchanger surface temperatures. The low alloyed boiler tubes had suffered severely with a corrosion rate as high as 2. mm/year, whereas dense thermal spray coatings offered excellent protection during the exposure.", keywords = "Biomass, Chlorine corrosion, Corrosion protection, High temperature corrosion, HVOF, Thermal spray coating", author = "Maria Oksa and Tommi Varis and Kimmo Ruusuvuori", year = "2014", month = "7", day = "25", doi = "10.1016/j.surfcoat.2014.04.025", language = "English", volume = "251", pages = "191--200", journal = "Surface & Coatings Technology", issn = "0257-8972", publisher = "Elsevier", }
@article{fafae41c8ffe4c419576f50fb11afa6f, title = "Accurate description of calcium solvation in concentrated aqueous solutions", abstract = "Calcium is one of the biologically most important ions; however, its accurate description by classical molecular dynamics simulations is complicated by strong electrostatic and polarization interactions with surroundings due to its divalent nature. Here, we explore the recently suggested approach for effectively accounting for polarization effects via ionic charge rescaling and develop a new and accurate parametrization of the calcium dication. Comparison to neutron scattering and viscosity measurements demonstrates that our model allows for an accurate description of concentrated aqueous calcium chloride solutions. The present model should find broad use in efficient and accurate modeling of calcium in aqueous environments, such as those encountered in biological and technological applications.", author = "Miriam Kohagen and Mason, {Philip E.} and Pavel Jungwirth", year = "2014", month = "7", day = "17", doi = "10.1021/jp5005693", language = "English", volume = "118", pages = "7902--7909", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "28", }
@article{0843aeb2f5434c6093d202db23e5a657, title = "Surface behavior of hydrated guanidinium and ammonium ions: A comparative study by photoelectron spectroscopy and molecular dynamics", abstract = "Through the combination of surface sensitive photoelectron spectroscopy and molecular dynamics simulation, the relative surface propensities of guanidinium and ammonium ions in aqueous solution are characterized. The fact that the N 1s binding energies differ between these two species was exploited to monitor their relative surface concentration through their respective photoemission intensities. Aqueous solutions of ammonium and guanidinium chloride, and mixtures of these salts, have been studied in a wide concentration range, and it is found that the guanidinium ion has a greater propensity to reside at the aqueous surface than the ammonium ion. A large portion of the relative excess of guanidinium ions in the surface region of the mixed solutions can be explained by replacement of ammonium ions by guanidinium ions in the surface region in combination with a strong salting-out effect of guanidinium by ammonium ions at increased concentrations. This interpretation is supported by molecular dynamics simulations, which reproduce the experimental trends very well. The simulations suggest that the relatively higher surface propensity of guanidinium compared with ammonium ions is due to the ease of dehydration of the faces of the almost planar guanidinium ion, which allows it to approach the water-vapor interface oriented parallel to it.", author = "Josephina Werner and Erik Wernersson and Victor Ekholm and Niklas Ottosson and Gunnar {\"O}hrwall and Jan Heyda and Ingmar Persson and Johan S{\"o}derstr{\"o}m and Pavel Jungwirth and Olle Bj{\"o}rneholm", year = "2014", month = "6", day = "26", doi = "10.1021/jp500867w", language = "English", volume = "118", pages = "7119--7127", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "25", }
@article{a0293f6b897948b99cf7b07c17f27a2e, title = "Carbon nanotubes-filled thermoplastic polyurethane-urea and carboxylated acrylonitrile butadiene rubber blend nanocomposites", abstract = "This article reports the preparation and characterization of multiwalled carbon nanotubes (MWCNTs)-filled thermoplastic polyurethane-urea (TPUU) and carboxylated acrylonitrile butadiene rubber (XNBR) blend nanocomposites. The dispersion of the MWCNTs was carried out using a laboratory two roll mill. Three different loadings, that is, 1, 3, and 5 wt {\%} of the MWCNTs were used. The electron microscopy image analysis proves that the MWCNTs are evenly dispersed along the shear flow direction. Through incorporation of the nanotubes in the blend, the tensile modulus was increased from 9.90 ± 0.5 to 45.30 ± 0.3 MPa, and the tensile strength at break was increased from 25.4 ± 2.5 to 33.0 ± 1.5 MPa. The wide angle X-ray scattering result showed that the TPUU:XNBR blends were arranged in layered structures. These structures are formed through chemical reactions of -NH group from urethane and urea with the carboxylic group on XNBR. Furthermore, even at a very low loading, the high degree of nanotubes dispersion results in a significant increase in the electrical percolation threshold. {\circledC} 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40341.", keywords = "blends, elastomers, graphene and fullerenes, nanotubes, polyurethanes, rubber", author = "Nasir Mahmood and Khan, {Asad Ullah} and St{\"o}ckelhuber, {Klaus Werner} and Amit Das and Dieter Jehnichen and Gert Heinrich", year = "2014", month = "6", day = "5", doi = "10.1002/app.40341", language = "English", volume = "131", journal = "Journal of Applied Polymer Science", issn = "0021-8995", publisher = "Wiley", number = "11", }
@article{86e14cb432424f81a9ad36d704ae06ab, title = "Damage mechanisms and cracking behavior of thermal sprayed WC-CoCr coating under scratch testing", abstract = "Evaluation of wear mechanisms of thick thermal sprayed cermet coatings is a challenging endeavor given the numerous process-induced structural and chemical changes as well as presence of residual stresses. In an effort to understand the damage processes under contact load and their sensitivity to the process induced microstructural attributes, controlled scratch testing was used. Detailed assessment of the resultant damage zone provided repeatable cracking patterns that are categorized as (i) Localized collapsing of material, (ii) angular cracks, (iii) primary semi-circular and developed semi-circular cracks and (iv) splat delamination. A correlation was established by linking observed damage mechanisms to the process induced microstructural descriptions including role of spray particle conditions and residual stresses. Quantitative correlations between delamination load for cracking and the process induced variable including particle properties as described by the non-dimensional melting index concept as well as residual stresses were established. Melting index captures the combined effect of particles[U+05F3] thermal and kinetic history and thus coating porosity and the process induced decarburization. The results highlight the critical role of coating density and stress evolution during the coating formation. The research points to scratch testing as a powerful evaluation method to characterize contact response of thick thermal spray cermet coatings including operative mechanisms.", keywords = "Damage mechanism, Scratch test, Sliding wear, Thermal spray coating", author = "Arash Ghabchi and Sanjay Sampath and Kenneth Holmberg and Tommi Varis", year = "2014", month = "5", day = "15", doi = "10.1016/j.wear.2014.02.017", language = "English", volume = "313", pages = "97--105", journal = "Wear", issn = "0043-1648", publisher = "Elsevier", number = "1-2", }
@article{69622e9b57534b4d9fcbe8fdc30ba42f, title = "Microphase mechanism of {"}superquenching{"} of luminescent probes in aqueous solutions of DNA and some other polyelectrolytes", abstract = "A new approach in terms of microphase model of aqueous solutions of polyelectrolytes is proposed for explanation of a very strong quenching of luminescent probes ({"}superquenching{"}) in these solutions. This phenomenon is used in literature for creation of extremely sensitive chemical and biosensors and was attributed predominantly to efficient energy or electron transfer. Microphase approach considers this phenomenon in terms of local concentrations of both the luminescent compound and of the quencher in microphase, formed by DNA and other polyelectrolytes, which can be several (4-10) orders of magnitude greater than their apparent concentrations in solution. Large local concentrations of the light absorbing centers in the microphase also provide conditions for aggregation of these centers and efficient energy transfer, which provides a significant increase in quenching constants (∼102-105). Microphase approach provides good quantitative description of all the features of the superquenching, new possibilities for analysis and control of kinetics of DNA reactions, and for improvement of the sensitivity of luminescent sensors. It reveals nonspecific localization of the luminescent centers and of Aun nanoparticles in different positions of DNA molecules that hinders from the simultaneous use of optical methods and electron or tunneling microscopy for the combined study of the structure of DNA.", author = "Kuzmin, {Michael G.} and Soboleva, {Irina V.} and Durandin, {Nikita A.} and Lisitsyna, {Ekaterina S.} and Kuzmin, {Vladimir A.}", year = "2014", month = "4", day = "17", doi = "10.1021/jp500713q", language = "English", volume = "118", pages = "4245--4252", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "15", }
@article{1750a48bc9684fee96b5f48e30cbe16b, title = "Azopolymer-based micro- and nanopatterning for photonic applications", abstract = "Azopolymers comprise a unique materials platform, in which the photoisomerization reaction of azobenzene molecules can induce substantial material motions at molecular, mesoscopic, and even macroscopic length scales. In particular, amorphous azopolymer films can form stable surface relief patterns upon exposure to interfering light. This allows obtaining large-area periodic micro- and nanostructures in a remarkably simple way. Herein, recent progress in the development of azopolymer-based surface-patterning techniques for photonic applications is reviewed. Starting with a thin azopolymer layer, one can create a variety of photonic elements, such as diffraction gratings, microlens arrays, plasmonic sensors, antireflection coatings, and nanostructured light-polarization converters, either by using the azopolymer surface patterns themselves as optical elements or by utilizing them to microstructure or nanostructure other materials. Both of these domains are covered, with the aim of triggering further research in this fascinating field of science and technology that is far from being harnessed. {\circledC} 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 163-182 The aim of this review is to cover the existing research and trigger future research on the development of azopolymer-based micro- and nanopatterning techniques for applications in photonics. These techniques exploit a remarkably simple inscription of large-area surface relief gratings on azopolymer films. Starting with such an azopolymer pattern, one can create a variety of photonic elements, including diffraction gratings, distributed Bragg reflectors, microlens arrays, plasmonic sensors, antireflection coatings, and nanostructured converters of light polarization.", keywords = "azo polymers, isomer/isomerization, lithography, nanotechnology, periodic arrays, photonics; surface-relief grating", author = "Arri Priimagi and Andriy Shevchenko", year = "2014", month = "2", day = "1", doi = "10.1002/polb.23390", language = "English", volume = "52", pages = "163--182", journal = "Journal of Polymer Science. Part B, Polymer Physics", issn = "0887-6266", publisher = "Wiley", number = "3", }
@article{223a27d0d44d4031a67de0e5e1b4d974, title = "Both zundel and eigen isomers contribute to the IR spectrum of the gas-phase H9O4 + cluster", abstract = "The {"}Eigen cation{"}, H3O+(H 2O)3, is the most prevalent protonated water structure in the liquid phase and the most stable gas-phase isomer of the H +(H2O)4 cluster. Nevertheless, its 50 K argon predissociation vibrational spectrum contains unexplainable low frequency peak(s). We have simulated the IR spectra of 10 gas-phase H+(H 2O)4 isomers, that include zero to three argon ligands, using dipole autocorrelation functions from ab initio molecular dynamics with the CP2K software. We have also tested the effect of elevated temperature and dispersion correction. The Eigen isomers describe well the high frequency portion of the spectrum but do not agree with experiment below 2000 cm -1. Most notably, they completely lack the {"}proton transfer bands{"} observed at 1050 and 1750 cm-1, which characterize Zundel-type (H5O2+) isomers. In contrast, linear isomers with a Zundel core, although not the lowest in energy, show very good agreement with experiment, particularly at low frequencies. Peak assignments made with partial velocity autocorrelation functions verify that the 1750 cm-1 band does not originate with the Eigen isomer but is rather due to coupled proton transfer/water bend in the Zundel isomer.", author = "Waldemar Kulig and Noam Agmon", year = "2014", month = "1", day = "9", doi = "10.1021/jp410446d", language = "English", volume = "118", pages = "278--286", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "1", }
@article{a041f8f641664de6bd44f29df34f72ae, title = "Stearate Modified Zinc-Aluminum Layered Double Hydroxides and Acrylonitrile Butadiene Rubber Nanocomposites", abstract = "The aim of this investigation is to highlight the potentials of layered double hydroxides (LDH) and to serve as a replacement for zinc oxide and stearic acid from the basic rubber formulation. This will eventually result in about a 10× significant reduction of Zn2+ ion concentration in the final compound. The unique advantage of stearate ion-modified LDH is the delivery of zinc ions to accelerate and stearate ions to activate the vulcanization process. Furthermore, it can also reinforce the rubber matrix by virtue of its layered structure as nanofiller.", keywords = "Layered double hydroxide, Nitrile rubber, Sulfur vulcanization, Zinc oxide", author = "Eshwaran, {S. B.} and D. Basu and B. Kutlu and A. Leuteritz and U. Wagenknecht and St{\"o}ckelhuber, {K. W.} and K. Naskar and A. Das and G. Heinrich", year = "2014", month = "1", doi = "10.1080/03602559.2013.843690", language = "English", volume = "53", pages = "65--73", journal = "Polymer-Plastics Technology and Engineering", issn = "0360-2559", publisher = "Taylor & Francis", number = "1", }
@inproceedings{b325d1e1a61945a6bc0941acebbfb963, title = "Abrasion and compression resistance of liquid-flame-spray-deposited functional nanoparticle coatings on paper", author = "Milena Stepien and Gary Chinga-Carrasco and Saarinen, {Jarkko J.} and Hannu Teisala and Mikko Tuominen and Janne Haapanen and Jurkka Kuusipalo and M{\"a}kel{\"a}, {Jyrki M.} and Martti Toivakka", note = "ORG=mol,0.5 ORG=fys,0.5 EXT={"}Tuominen, Mikko{"}", year = "2014", language = "English", isbn = "9781510801295", pages = "68--82", booktitle = "13th TAPPI Advanced Coating Fundamentals Symposium 2014", publisher = "TAPPI Press", address = "United States", }
@article{36355a89725349a59af5d725677c14a5, title = "Effect of non-rubber components of NR on the carbon nanotube (CNT) localization in SBR/NR blends", abstract = "Carbon nanotubes (CNTs) are mixed into SBR/NR and SBR/IR blends using a wet mixing process. The phase specific localization of CNTs in rubber blends is predicted theoretically using surface energy data of blend components and determined experimentally by means of the wetting concept. Almost all CNTs are found to be localized in the SBR matrix of SBR/IR blends due to the better affinity of CNTs to SBR than to IR. In contrast, a high CNT loading localized in the NR phase of SBR/NR blends results from the presence of phospholipids in NR. Electrical and mechanical properties of the rubber blends depend strongly on CNT localization. A lower CNT loading in SBR matrix of SBR/NR blends imparts a better wet grip and lower rolling resistance to tire tread compounds.", keywords = "carbon nanotubes, filler localization, nanocomposites, rubber blends", author = "Le, {Hai Hong} and Meenali Parsekar and Sybill Ilisch and Sven Henning and Amit Das and St{\"o}ckelhuber, {Klaus Werner} and Mario Beiner and Ho, {Chi Anh} and Rameshwar Adhikari and Sven Wie{\ss}ner and Gert Heinrich and Radusch, {Hans Joachim}", year = "2014", doi = "10.1002/mame.201300254", language = "English", volume = "299", pages = "569--582", journal = "Macromolecular Materials and Engineering", issn = "1438-7492", publisher = "WILEY-V C H VERLAG GMBH", number = "5", }
@article{0d7a208861164223b69ea6bfc8ab54f5, title = "Formation mechanisms, structure, and properties of HVOF-sprayed WC-CoCr coatings: An approach toward process maps", abstract = "Our study focuses on understanding the damage tolerance and performance reliability of WC-CoCr coatings. In this paper, the formation of HVOF-sprayed tungsten carbide-based cermet coatings is studied through an integrated strategy: First-order process maps are created by using online-diagnostics to assess particle states in relation to process conditions. Coating properties such as hardness, wear resistance, elastic modulus, residual stress, and fracture toughness are discussed with a goal to establish a linkage between properties and particle characteristics via second-order process maps. A strong influence of particle state on the mechanical properties, wear resistance, and residual stress stage of the coating was observed. Within the used processing window (particle temperature ranged from 1687 to 1831 °C and particle velocity from 577 to 621 m/s), the coating hardness varied from 1021 to 1507 HV and modulus from 257 to 322 GPa. The variation in coating mechanical state is suggested to relate to the microstructural changes arising from carbide dissolution, which affects the properties of the matrix and, on the other hand, cohesive properties of the lamella. The complete tracking of the coating particle state and its linking to mechanical properties and residual stresses enables coating design with desired properties.", keywords = "fracture toughness, HVOF, process map, residual stress, WC-CoCr", author = "T. Varis and T. Suhonen and A. Ghabchi and A. Valarezo and S. Sampath and X. Liu and Hannula, {S. P.}", year = "2014", doi = "10.1007/s11666-014-0110-5", language = "English", volume = "23", pages = "1009--1018", journal = "Journal of Thermal Spray Technology", issn = "1059-9630", publisher = "ASM International", number = "6", }
@article{e9101949ed104113b93f6c72fa25c70e, title = "The effects of UV irradiation to polyetheretherketone fibres: Characterization by different techniques", abstract = "The effects of UV irradiation on polyetheretherketone (PEEK) fibres were investigated in this study. PEEK fibres were manufactured with a melt spinning system and then artificially aged with simulated solar UV light. Fibres were then characterized by mechanical tests, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), rheology, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). PEEK, best known for its excellent thermal stability, suffered greatly from the effects of UV irradiation. The low UV stability manifested as embrittlement of the fibres in the mechanical tests, increased crosslinking rate in the rheological tests, formation of carbonyl and hydroxyl groups and changes in the nature of the carbon-hydrogen bonds in the FTIR, diminished thermal properties in TGA, and transverse cracks in the SEM photos. DSC was found to be an inaccurate technique for estimating the degradation level of PEEK fibres, whereas the carbonyl index measured by FTIR was found to be the most convenient technique. {\circledC} 2014 Elsevier Ltd. All rights reserved.", keywords = "PEEK, Fibre, Ultraviolet, Rheology, POLY(ETHER ETHER KETONE), STRUCTURE/DEGRADABILITY RELATIONSHIPS, SCANNING CALORIMETRY, THERMAL-DEGRADATION, POLYPROPYLENE, PHOTODEGRADATION, POLYMERS, PHOTOOXIDATION, CRYSTALLINITY", author = "Ville Myll{\"a}ri and Ruoko, {Tero Petri} and Pentti J{\"a}rvel{\"a}", note = "Contribution: organisation=mol,FACT1=0.8Contribution: organisation=keb,FACT2=0.2Portfolio EDEND: 2014-09-10Publisher name: Elsevier Ltd", year = "2014", doi = "10.1016/j.polymdegradstab.2014.08.003", language = "English", volume = "109", pages = "278--284", journal = "Polymer Degradation and Stability", issn = "0141-3910", publisher = "Elsevier", }
@article{3dcce00e50234d3eaeae8a6a95434f0a, title = "Self-assembly of polystyrene-block-poly(4-vinylpyridine) block copolymer on molecularly functionalized silicon substrates: Fabrication of inorganic nanostructured etchmask for lithographic use", abstract = "Block copolymers (BCPs) are seen as a possible cost effective complementary technique to traditional lithography currently used in the semiconductor industry. This unconventional approach has received increased attention in recent years as a process capable of facilitating the ever decreasing device size demanded. Control over microdomain orientation and enhancing long range order are key aspects for the utility of BCPs for future lithographic purposes. This paper provides an efficient route for the fabrication of highly ordered nanostructures suitable for such application. We investigate the significant effect of surface treatment regarding the self-assembly process of polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) by employing an ethylene glycol layer, producing well defined perpendicular P4VP cylinders with long range order over large surface areas. Nanopores are generated through surface reconstruction using a preferential solvent, which allows for the incorporation of an inorganic moiety. Treatment of this pattern with UV/Ozone leads to formation of well-ordered iron oxide nanodots with a pitch of ∼26 nm. Furthermore, high aspect ratio silicon nanopillars result following pattern transfer (using Ar/O2).", author = "C. Cummins and D. Borah and S. Rasappa and A. Chaudhari and T. Ghoshal and O'Driscoll, {B. M D} and P. Carolan and N. Petkov and Holmes, {J. D.} and Morris, {M. A.}", year = "2013", month = "12", day = "21", doi = "10.1039/c3tc31498g", language = "English", volume = "1", pages = "7941--7951", journal = "Journal of Materials Chemistry C", issn = "2050-7526", publisher = "Royal Society of Chemistry", number = "47", }
@article{691d4107221148b586bf2d7443d1f546, title = "Effect of surface morphology of poly({\"i}μ-caprolactone) scaffolds on adipose stem cell adhesion and proliferation", abstract = "Summary The effect of the surface morphology of flat poly({\"I}μ- caprolactone) (PCL) scaffolds on human adipose stem cell (hASC) adherence and proliferation was studied. During fabrication of the scaffolds by phase inversion, the employment of different non-solvents (water (W), ethanol (EtOH) or isopropanol (IPA)) led to distinct surface morphologies. It was found that PCL scaffolds fabricated using IPA as a non-solvent had a higher roughness and porosity compared to the other groups. Moreover, during culturing of hASCs under static conditions, best cell attachment, spreading and growth were observed on the PCL scaffold. Our results show the potential of PCL scaffolds prepared using IPA as a non-solvent for especially soft tissue engineering applications.", keywords = "morphology, phase inversion, poly({\"I}μ-caprolactone), roughness, scaffold porosity", author = "Nazely Diban and Haimi, {Suvi P.} and Lydia Bolhuis-Versteeg and Sandra Teixeira and Susanna Miettinen and Poot, {Andr{\'e} A.} and Grijpma, {Dirk W.} and Dimitrios Stamatialis", year = "2013", month = "12", doi = "10.1002/masy.201300106", language = "English", volume = "334", pages = "126--132", journal = "Macromolecular symposia", issn = "1022-1360", publisher = "Wiley-VCH Verlag", number = "1", }
@article{7966f83e54b14dc68e9e097e060bc551, title = "Human adipose stem cells in chondrogenic differentiation medium without growth factors differentiate towards annulus fibrosus phenotype in vitro", abstract = "Summary Intervertebral disc degeneration is the main cause of chronic back pain. Disc degeneration mainly leads to tearing of annulus fibrosus (AF), which is with current methods difficult to restore and impossible to regenerate. Stem cell technology offers a potential technique to repair the ruptured AF by enabling new matrix synthesis at the defect site. Previous studies have shown that human adipose stem cells (hASCs) are able to differentiate towards AF phenotype when treated with suitable growth factors. There are concerns about the use of growth factors in clinical applications because of their short half-lives, high costs and low effectiveness. The main aim of this research project was to regenerate AF tissue in vitro using hASCs and serum free chondrogenic medium without supplementation of growth factors. Differentiation of hASCs was induced by using the micromass culture technique. Human annulus fibrosus cell (hAFCs) cultured in commercial AF growth medium were used as positive control. Assessment of AF phenotype of hASCs and hAFCs was done at 14 and 21 days of culture. Quantification of sulphated glycosaminoglycan (GAG) content showed that hASCs cultured in chondrogenic medium expressed similar levels of sulphated GAGs as hAFCs. qRT-PCR confirmed the similarity of the differentiated hASCs with AF phenotype. Several markers for AF phenotype (aggrecan, collagen type I and glypican-3) were expressed in both hAFCs and differentiated hASCs. This is the first study that demonstrated that hASCs can be differentiated towards AF phenotype using serum free chondrogenic medium without growth factors. In a next step, scaffolds manufactured from biodegradable polymers will be used in combination with ASCs to find an optimal construct to repair AF defects.", keywords = "adipose stem cells, annulus fibrosus, intervertebral disc, tissue engineering", author = "Gebraad, {A. W H} and S. Miettinen and Grijpma, {D. W.} and Haimi, {S. P.}", year = "2013", month = "12", doi = "10.1002/masy.201300104", language = "English", volume = "334", pages = "49--56", journal = "Macromolecular symposia", issn = "1022-1360", publisher = "Wiley-VCH Verlag", number = "1", }
@article{fc3f8431045c443ca764ba882c9af14b, title = "Proliferation and differentiation of adipose stem cells towards smooth muscle cells on poly(trimethylene carbonate) membranes", abstract = "Summary Multipotent human adipose stem cells (hASCs) are an abundant and potential source of cells for vascular tissue engineering when combined with a suitable biomaterial scaffold. Poly(trimethylene carbonate) (PTMC) has been shown to be a useful biodegradable material for tissue engineered vascular grafts due to its flexibility, excellent biocompatibility and enzymatic degradation by surface erosion in vivo. The purpose of the current study was to evaluate the proliferation and differentiation of hASCs towards smooth muscle cells (SMCs) on gamma-crosslinked and photo-crosslinked PTMC membranes. PTMC macromers were functionalized with methacrylate end groups and crosslinked by UV initiated radical polymerization. High molecular weight linear PTMC was crosslinked by gamma irradiation. Cell viability, cell numbers and SMC differentiation of hASCs were evaluated on the differently crosslinked PTMC films at 7 and 14 days (d). On the photo-crosslinked membranes, homogenous monolayers of hASC were detected by live/dead assay. Consistently, cells on the photo-crosslinked membranes had significantly higher cell numbers compared to cells on the gamma-crosslinked membranes after 14 d of culture. SMC specific genes were expressed on both membranes at 14 d. Photo-crosslinked membranes showed higher expression of SMC specific proteins at 14 d compared to gamma-crosslinked membranes. These results suggest that especially the photo-crosslinked PTMC membranes are suitable for vascular tissue engineering applications when combined with hASCs.", keywords = "adipose stem cell differentiation, poly (trimethylene carbonate), smooth muscle cells, tissue engineering", author = "German, {Salvador Jimenez} and Mehdi Behbahani and Susanna Miettinen and Grijpma, {Dirk W.} and Haimi, {Suvi P.}", year = "2013", month = "12", doi = "10.1002/masy.201300100", language = "English", volume = "334", pages = "133--142", journal = "Macromolecular symposia", issn = "1022-1360", publisher = "Wiley-VCH Verlag", number = "1", }
@article{09dc53a70f9c4fb286c457d1f108d0a5, title = "Release of halide ions from the buried active site of the haloalkane dehalogenase LinB revealed by stopped-flow fluorescence analysis and free energy calculations", abstract = "Release of halide ions is an essential step of the catalytic cycle of haloalkane dehalogenases. Here we describe experimentally and computationally the process of release of a halide anion from the buried active site of the haloalkane dehalogenase LinB. Using stopped-flow fluorescence analysis and umbrella sampling free energy calculations, we show that the anion binding is ion-specific and follows the ordering I- > Br- > Cl-. We also address the issue of the protonation state of the catalytic His272 residue and its effect on the process of halide release. While deprotonation of His272 increases binding of anions in the access tunnel, we show that the anionic ordering does not change with the switch of the protonation state. We also demonstrate that a sodium cation could relatively easily enter the active site, provided the His272 residue is singly protonated, and replace thus the missing proton. In contrast, Na+ is strongly repelled from the active site containing the doubly protonated His272 residue. Our study contributes toward understanding of the reaction mechanism of haloalkane dehalogenase enzyme family. Determination of the protonation state of the catalytic histidine throughout the catalytic cycle remains a challenge for future studies.", author = "Jana Hladilkova and Zbynek Prokop and Radka Chaloupkova and Jiri Damborsky and Pavel Jungwirth", year = "2013", month = "11", day = "21", doi = "10.1021/jp409040u", language = "English", volume = "117", pages = "14329--14335", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "46", }
@article{0187f52a7a4d4ba788020d720c018065, title = "How conformational flexibility stabilizes the hyperthermophilic elongation factor G-domain", abstract = "Proteins from thermophilic organisms are stable and functional well above ambient temperature. Understanding the molecular mechanism underlying such a resistance is of crucial interest for many technological applications. For some time, thermal stability has been assumed to correlate with high mechanical rigidity of the protein matrix. In this work we address this common belief by carefully studying a pair of homologous G-domain proteins, with their melting temperatures differing by 40 K. To probe the thermal-stability content of the two proteins we use extensive simulations covering the microsecond time range and employ several different indicators to assess the salient features of the conformational landscape and the role of internal fluctuations at ambient condition. At the atomistic level, while the magnitude of fluctuations is comparable, the distribution of flexible and rigid stretches of amino-acids is more regular in the thermophilic protein causing a cage-like correlation of amplitudes along the sequence. This caging effect is suggested to favor stability at high T by confining the mechanical excitations. Moreover, it is found that the thermophilic protein, when folded, visits a higher number of conformational substates than the mesophilic homologue. The entropy associated with the occupation of the different substates and the thermal resilience of the protein intrinsic compressibility provide a qualitative insight on the thermal stability of the thermophilic protein as compared to its mesophilic homologue. Our findings potentially open the route to new strategies in the design of thermostable proteins.", author = "Maria Kalimeri and Obaidur Rahaman and Simone Melchionna and Fabio Sterpone", note = "EXT={"}Kalimeri, Maria{"}", year = "2013", month = "11", day = "7", doi = "10.1021/jp407078z", language = "English", volume = "117", pages = "13775--13785", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "44", }
@article{184c769e992e47b7ab31133d5c1e659d, title = "Spectroscopic study of a DNA brush synthesized in situ by surface initiated enzymatic polymerization", abstract = "We used a combination of synchrotron-based X-ray photoelectron spectroscopy (XPS) and angle-resolved near-edge X-ray absorption fine structure (NEXAFS) spectroscopy to study the chemical integrity, purity, and possible internal alignment of single-strand (ss) adenine deoxynucleotide (poly(A)) DNA brushes. The brushes were synthesized by surface-initiated enzymatic polymerization (SIEP) on a 25-mer of adenine self-assembled monolayer (SAM) on gold (A25-SH), wherein the terminal 3′-OH of the A25-SH serve as the initiation sites for SIEP of poly(A). XPS and NEXAFS spectra of poly(A) brushes were found to be almost identical to those of A25-SH initiator, with no unambiguous traces of contamination. Apart from the well-defined chemical integrity and contamination-free character, the brushes were found to have a high degree of orientational order, with an upright orientation of individual strands, despite their large thickness up to ∼55 nm, that corresponds to a chain length of at least several hundred nucleotides for individual ssDNA molecules. The orientational order exhibited by these poly(A) DNA brushes, mediated presumably by base stacking, was found to be independent of the brush thickness as long as the packing density was high enough. The well-defined character and orientational ordering of the ssDNA brushes make them a potentially promising system for different applications.", author = "Khan, {M. Nuruzzaman} and Vinalia Tjong and Ashutosh Chilkoti and Michael Zharnikov", year = "2013", month = "8", day = "29", doi = "10.1021/jp404774x", language = "English", volume = "117", pages = "9929--9938", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "34", }
@article{3d5a1cae3f91443d8af8fb07a5b34211, title = "Reversal of the hofmeister series: Specific ion effects on peptides", abstract = "Ion-specific effects on salting-in and salting-out of proteins, protein denaturation, as well as enzymatic activity are typically rationalized in terms of the Hofmeister series. Here, we demonstrate by means of NMR spectroscopy and molecular dynamics simulations that the traditional explanation of the Hofmeister ordering of ions in terms of their bulk hydration properties is inadequate. Using triglycine as a model system, we show that the Hofmeister series for anions changes from a direct to a reversed series upon uncapping the N-terminus. Weakly hydrated anions, such as iodide and thiocyanate, interact with the peptide bond, while strongly hydrated anions like sulfate are repelled from it. In contrast, reversed order in interactions of anions is observed at the positively charged, uncapped N-terminus, and by analogy, this should also be the case at side chains of positively charged amino acids. These results demonstrate that the specific chemical and physical properties of peptides and proteins play a fundamental role in ion-specific effects. The present study thus provides a molecular rationalization of Hofmeister ordering for the anions. It also provides a route for tuning these interactions by titration or mutation of basic amino acid residues on the protein surface.", author = "Jana Paterov{\'a} and Rembert, {Kelvin B.} and Jan Heyda and Yadagiri Kurra and Okur, {Halil I.} and Liu, {Wenshe R.} and Christian Hilty and Cremer, {Paul S.} and Pavel Jungwirth", year = "2013", month = "7", day = "11", doi = "10.1021/jp405683s", language = "English", volume = "117", pages = "8150--8158", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "27", }
@article{630b894a0f544d4499f153e022367c76, title = "Development and application of HVOF sprayed spinel protective coating for SOFC interconnects", abstract = "Protective coatings are needed for metallic interconnects used in solid oxide fuel cell (SOFC) stacks to prevent excessive high-temperature oxidation and evaporation of chromium species. These phenomena affect the lifetime of the stacks by increasing the area-specific resistance (ASR) and poisoning of the cathode. Protective MnCo2O4 and MnCo1.8Fe 0.2O4 coatings were applied on ferritic steel interconnect material (Crofer 22 APU) by high velocity oxy fuel spraying. The substrate-coating systems were tested in long-term exposure tests to investigate their high-temperature oxidation behavior. Additionally, the ASRs were measured at 700 C for 1000 h. Finally, a real coated interconnect was used in a SOFC single-cell stack for 6000 h. Post-mortem analysis was carried out with scanning electron microscopy. The deposited coatings reduced significantly the oxidation of the metal, exhibited low and stable ASR and reduced effectively the migration of chromium.", keywords = "ASR, HVOF spraying, interconnect, protective coating, SOFC, spinel, stack testing", author = "O. Thomann and M. Pihlatie and M. Rautanen and O. Himanen and J. Lagerbom and M. M{\"a}kinen and T. Varis and T. Suhonen and J. Kiviaho", year = "2013", month = "6", doi = "10.1007/s11666-012-9880-9", language = "English", volume = "22", pages = "631--639", journal = "Journal of Thermal Spray Technology", issn = "1059-9630", publisher = "ASM International", number = "5", }
@article{1cd1a1b8d0484c93af3b16897923d9e0, title = "Increased lifetime for biomass and waste to energy power plant boilers with HVOF coatings: High temperature corrosion testing under chlorine-containing molten salt", abstract = "Heat exchanger surfaces of waste to energy and biomass power plant boilers experience often severe corrosion due to very aggressive components in the used fuels. High velocity oxy-fuel (HVOF) coatings offer excellent protection for boiler tubes against high temperature corrosion due to their high density and good adherence to the substrate material. Several thermal spray coatings with high chromium content were sprayed with HVOF technique. Their mechanical properties and high temperature corrosion resistance were tested and analyzed. The coating materials included NiCr, IN625, Ni-21Cr-10W-9Mo-4Cu, and iron-based partly amorphous alloy SHS9172 (Fe-25Cr-15W-12Nb-6Mo). High temperature corrosion testing was performed in NaCl-KCl-Na2SO4 salt with controlled H2O atmosphere at 575 and 625 C. The corrosion test results of the coatings were compared to corrosion resistance of tube materials (X20, Alloy 263 and Sanicro 25).", keywords = "biofuel, CJS, coating characteristics, corrosion protection coating, high temperature corrosion, HVOF, molten salt, process optimization, waste to energy", author = "Maria Oksa and Satu Tuurna and Tommi Varis", year = "2013", month = "6", doi = "10.1007/s11666-013-9928-5", language = "English", volume = "22", pages = "783--796", journal = "Journal of Thermal Spray Technology", issn = "1059-9630", publisher = "ASM International", number = "5", }
@article{a0db8fe6ebff42a5a057acdd249fdfad, title = "Cation-specific effects on enzymatic catalysis driven by interactions at the tunnel mouth", abstract = "Cationic specificity which follows the Hofmeister series has been established for the catalytic efficiency of haloalkane dehalogenase LinB by a combination of molecular dynamics simulations and enzyme kinetic experiments. Simulations provided a detailed molecular picture of cation interactions with negatively charged residues on the protein surface, particularly at the tunnel mouth leading to the enzyme active site. On the basis of the binding affinities, cations were ordered as Na+ > K+ > Rb+ > Cs+. In agreement with this result, a steady-state kinetic analysis disclosed that the smaller alkali cations influence formation and productivity of enzyme-substrate complexes more efficiently than the larger ones. A subsequent systematic investigation of two LinB mutants with engineered charge in the cation-binding site revealed that the observed cation affinities are enhanced by increasing the number of negatively charged residues at the tunnel mouth, and vice versa, reduced by decreasing this number. However, the cation-specific effects are overwhelmed by strong electrostatic interactions in the former case. Interestingly, the substrate inhibition of the mutant LinB L177D in the presence of chloride salts was 7 times lower than that of LinB wild type in glycine buffer. Our work provides new insight into the mechanisms of specific cation effects on enzyme activity and suggests a potential strategy for suppression of substrate inhibition by the combination of protein and medium engineering.", author = "Veronika Štěp{\'a}nkov{\'a} and Jana Paterov{\'a} and Jiř{\'i} Damborsk{\'y} and Pavel Jungwirth and Radka Chaloupkov{\'a} and Jan Heyda", year = "2013", month = "5", day = "30", doi = "10.1021/jp401506v", language = "English", volume = "117", pages = "6394--6402", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "21", }
@article{2f5a7a45b9474fbdbf702a3336138394, title = "Immobilized bioactive agents onto polyurethane surface with heparin and phosphorylcholine group", abstract = "Heparin (HEP) and phosphorylcholine groups (PC) were grafted onto the polyurethane (PU) surface in order to improve biocompatibility and anticoagulant activity. After the surface grafting sites of PU were amplified with the primary amine groups of polyethylenimine (PEI), heparin was covalently linked onto the surface by the reaction between the amino group and the carboxyl group. PC groups were covalently immobilized on the PU-PEI surface through the reaction between the amino group and the aldehyde group of phosphorylcholine glyceraldehyde (PCGA). The surface density of primary amine groups was determined by a ninhydrin assay. The amino group density reached a maximum of 0.88 μmol/cm2 upon incorporation of 10 wt{\%} PEI. The amount of heparin covalently immobilized on the PU-PEI surface was determined by the toluidine blue method. The grafting chemistry resulted in the comparatively dense immobilization of HEP (2.6 μg/cm2) and PC to the PU-PEI surfaces. The HEP and PC modified surfaces were characterized by water uptake (PU 0.15 mg/cm2, PU-PEI 3.54 mg/cm2, PU-HEP 2.04 mg/cm2, PU-PC 2.38 mg/cm2), water contact angle (PU 95.3, PU-PEI 34.0, PU-HEP 39.5, PU-PC 37.2), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and scanning electron microscope (SEM). The results demonstrated that the PUPEI surface was successfully grafted with HEP and PC. The hydrophilicity and hemocompatibility of these grafted surfaces were significantly improved. These results suggested that the PU-HEP and PU-PC composite films are promising candidates for blood contacting tissue engineering.", keywords = "hemocompatibility, heparin, phosphorylcholine group, polyethylenimine, polyurethane", author = "Mingqi Tan and Yakai Feng and Heyun Wang and Li Zhang and Musammir Khan and Jintang Guo and Qingliang Chen and Jianshi Liu", year = "2013", month = "5", doi = "10.1007/s13233-013-1028-3", language = "English", volume = "21", pages = "541--549", journal = "Macromolecular Research", issn = "1598-5032", publisher = "Springer Verlag", number = "5", }
@article{780179a153d24e78a38460234a71fd9f, title = "Nanoindentation study of light-induced softening of supramolecular and covalently functionalized azo polymers", abstract = "Nanoindentation studies on thin films of the widely used azo polymer pDR1A and a supramolecular polymer-azobenzene complex p4VP(DY7)0.5 demonstrate significant light-induced softening upon visible-light irradiation due to trans-cis-trans photoisomerization of the azobenzene units. More specifically, the strain-rate sensitivities of pDR1A and p4VP(DY7)0.5 upon 532 nm irradiation increase by 80{\%} and 120{\%}, respectively. These results imply a photosoftening contribution to the mechanisms of light-induced surface patterning of azo polymers and the photomechanical effect. The finding that under the experimental conditions used photosoftening is more significant in the supramolecular complex than in the covalently functionalized polymer highlights the potential of noncovalent functionalization strategies in designing materials with efficient photomechanical response, and nanoindentation provides a powerful technique to quantify the connection between the photoinduced changes in mechanical properties and photoinduced macroscopic movement of azo polymer films.", author = "Jaana Vapaavuori and Zahid Mahimwalla and Chromik, {Richard R.} and Matti Kaivola and Arri Priimagi and Barrett, {Christopher J.}", year = "2013", month = "4", day = "28", doi = "10.1039/c3tc30246f", language = "English", volume = "1", pages = "2806--2810", journal = "Journal of Materials Chemistry C", issn = "2050-7526", publisher = "Royal Society of Chemistry", number = "16", }
@article{f559add9f2c64c9c9520c8ee78c065ca, title = "Biomimetic zinc chlorin-poly(4-vinylpyridine) assemblies: Doping level dependent emission-absorption regimes", abstract = "To develop biomimetic dye-polymers for photonics, two different types of Zn chlorin-poly(4-vinylpyridine) (P4VP) assemblies were prepared by varying Zn pyro-pheophorbide a methylester (ZnPPME) and Zn 31-OH-pyro- pheophorbide a methylester (Zn-31-OH-PPME) doping levels. 1H NMR spectroscopy and diffusion ordered NMR spectroscopy (DOSY) studies revealed that a coordinative interaction between Zn chlorin and P4VP was predominant in solution (d5-nitrobenzene). Small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) characterization of bulk samples of polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) doped with variable amounts of Zn chlorin showed that the pigment doping transformed the native cylindrical block copolymer nanostructures to lamellar morphologies. The result indicates that the pyridine moiety-Zn chlorin coordination is stronger than the aggregation tendency between the pigment molecules even in the solid state. UV-Vis absorption spectroscopy studies of a Zn chlorin-P4VP thin film showed characteristic monomeric chlorin spectra, while steady-state fluorescence spectroscopy displayed quenching of fluorescence and time-resolved studies indicated shortening of fluorescence lifetimes with an increasing chlorin doping level. Notably, time-resolved fluorescence spectroscopy revealed that the lifetime decay changed from monoexponential to biexponential above 0.5 wt{\%} (ca. 0.001 equiv.) loadings. The F{\"o}rster analysis implies that excitonic chlorin-chlorin interactions are observed in the thin films when the distance between the pigment molecules is approximately 50 {\AA}. The Zn chlorin-P4VP solid films emit strongly up to 1 wt{\%} (ca. 0.002 equiv.) doping level above which the chlorin-chlorin interactions start to linearly dominate with an increase of doping level, while with 10 wt{\%} (ca. 0.02 equiv.) loading less than 10{\%} of fluorescence remains. Doping levels up to 300 wt{\%} (0.5 equiv.) can be used in absorbing materials without the formation of chlorin aggregates. These defined optical response regions pave the way for photonic materials based on biopigment assemblies.", author = "Ville Pale and Taru Nikkonen and Jaana Vapaavuori and Mauri Kostiainen and Jari Kavakka and Jorma Selin and Ilkka Tittonen and Juho Helaja", year = "2013", month = "3", day = "21", doi = "10.1039/c3tc00499f", language = "English", volume = "1", pages = "2166--2173", journal = "Journal of Materials Chemistry C", issn = "2050-7526", publisher = "Royal Society of Chemistry", number = "11", }
@article{1336f78d40f64da6afff568cb1834c74, title = "Ab initio study of the surface properties of austenitic stainless steel alloys", abstract = "Using ab initio calculations we investigated the surface energies of paramagnetic Fe1 - c - nCrcNin random alloys within the concentration range of 0.12 ≤ c ≤ 0.32 and 0.04 ≤ n ≤ 0.32. These alloys crystallize mainly in the face centred cubic (fcc) structure and constitute the main building blocks of austenitic stainless steels. It is shown that all alloys have the lowest surface energies along the most close packed crystal orientation, namely the fcc (111) surfaces. The amount of Ni seems to have little effect on the surface energy, while almost all composition-driven change may be attributed to the changes in the Cr content. Within the studied compositional range, the change of the surface energy with the composition is of the order of 10{\%}. Trends of the surface energy can be related to the magnetic structure of surfaces. Using the total energy as a function of the concentration, we determine the effective chemical potentials in bulk and at the surface, which can be used to estimate the surface segregation energies.", keywords = "Alloy surface, Austenitic, FeCrNi, First-principles calculation, Stainless steel, Surface energy", author = "H. Pitk{\"a}nen and M. Alatalo and A. Puisto and M. Ropo and K. Kokko and L. Vitos", year = "2013", month = "3", doi = "10.1016/j.susc.2012.12.007", language = "English", volume = "609", pages = "190--194", journal = "Surcface Science", issn = "0039-6028", publisher = "Elsevier", }
@article{157c4ccb776c4caaa0bab7cc88d17e28, title = "Aqueous guanidinium-carbonate interactions by molecular dynamics and neutron scattering: Relevance to ion-protein interactions", abstract = "Guanidinium carbonate was used in this study as a simple proxy for the biologically relevant arginine-carbonate interactions in water. Molecular dynamics (MD) simulations of guanidinium carbonate were performed with nonpolarizible water using two implementations of the ion force fields. In the first, the ions had full charges, while in the second, the ions had reduced charges in order to effectively account for electronic polarization effects of water. The results from the simulations were then compared to data from previous neutron scattering experiments. It was found that there were significant discrepancies between the full charge force field MD simulations and the experimental results due to excessive ion pairing and clustering in the former. In contrast, reducing the ionic charges yields a more regular solution with a simulated structure, which fits well the experimental data.", author = "Mario Vazdar and Pavel Jungwirth and Mason, {Philip E.}", year = "2013", month = "2", day = "14", doi = "10.1021/jp310719g", language = "English", volume = "117", pages = "1844--1848", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "6", }
@article{9c91067ba30045c585229971f02da5d8, title = "Naturally occurring amino acids: A suitable substitute of N-N/-di-phenyl guanidine (DPG) in silica tyre formulation?", abstract = "N-N/-di-phenyl guanidine (DPG) in combination with cyclohexyl benzothiazole sulfenamide (CBS) is widely used as an accelerator for the vulcanization of silica filled solution styrene butadiene rubber (S-SBR). The vulcanizates thus obtained exhibit excellent mechanical properties, good dynamic properties and also good aging resistance property. However, the use of DPG is a bit restricted of late being reported to be a potent carcinogenic compound and, hence, the effective substitution for DPG by safe alternative has been extensively explored. In this study, we systematically study the effects of naturally occurring amino acid L-cystine (L-cys) and its derivative L-cystine dimethyl ester dihydrochloride (ELCH) as environmental friendly co-accelerators for the vulcanization of silicafilled S-SBR.", keywords = "L-cystine, N-N/-di-phenyl guanidine, Silica, Solution styrene butadiene rubber, Vulcanization", author = "Debnath, {Subhas Ch} and Amit Das and Debdipta Basu and G. Heinrich", year = "2013", month = "1", language = "English", volume = "66", pages = "25--31", journal = "KGK: KAUTSCHUK GUMMI KUNSTSTOFFE", issn = "0948-3276", publisher = "Huthig GmbH", number = "1-2", }
@article{0396e7e5c90944fcbf258d9149869de1, title = "Elastomer composites based on carbon nanotubes and ionic liquid", abstract = "Carbon nanotubes (CNTs) are known for excellent electrical conductivity and high elastic modulus. But difficulties arise in realizing their potential in matrices due to their existence in the form of aggregates or agglomerates. A simplified mixing technique using ionic liquid (IL) was developed to improve the dispersion of CNTs in elastomers. At first, CNTswere modified using an IL, 1-butyl-3-methyl-imidazolium-bis-(trifluoromethylsulfonyl)-imide in a mortar and pestle, and later, the modified tubes were incorporated into elastomers using a two-roll mill. The effect of modified tubes and IL on polar polychloroprene and nonpolar solution styrene butadiene rubber is studied. Enhanced dispersion and networking of CNTs can be achieved using this technique, based on which highly conducting composites were developed. Moreover, the composites with modified CNTs exhibited higher mechanical properties (tensile modulus, hardness) and thermal stability than the composites with unmodified CNTs. ILs are also found to have multifunctional roles (as antioxidants, as coupling agents) in the composites. The applications of composites with a particular focus on actuators and sensors are also discussed.", author = "Kalaivani Subramaniam and Amit Das and St{\"o}ckelhuber, {Klaus Werner} and Gert Heinrich", year = "2013", doi = "10.5254/rct.13.86984", language = "English", volume = "86", pages = "367--400", journal = "Rubber Chemistry and Technology", issn = "0035-9475", publisher = "Rubber Division of the American Chemical Society", number = "3", }
@article{fdbc17ae0db446b3908d604455d93f65, title = "Transforming anion instability into stability: Contrasting photoionization of three protonation forms of the phosphate ion upon moving into water", abstract = "We use photoelectron emission spectroscopy with vacuum microjet technique and quantum chemistry calculations to investigate electronic structure and stability of aqueous phosphate anions. On the basis of the measured photoelectron spectra of sodium phosphates at different pH, we report the lowest vertical ionization energies of monobasic (9.5 eV), dibasic (8.9 eV), and tribasic (8.4 eV) anions. Electron binding energies were in tandem modeled with ab initio methods, using a mixed dielectric solvation model together with up to 64 explicitly solvating water molecules. We demonstrate that two solvation layers of explicit water molecules are needed to obtain converged values of vertical ionization energies (VIEs) within this mixed solvation model, leading to very good agreement with experiment. We also show that the highly charged PO4 3- anion, which is electronically unstable in the gas phase, gains the electronic stability with about 16 water molecules, while only 2-3 water molecules are sufficient to stabilize the doubly charged phosphate anion. We also investigate the effect of ion pairing on the vertical ionization energy. In contrast to protonation (leading to a formation of covalent O-H bond), sodiation (leading to an anion···Na+ ion pair) has only a weak effect on the electron binding energy.", author = "Eva Pluhařov{\'a} and Milan Onč{\'a}k and Robert Seidel and Christi Schroeder and William Schroeder and Bernd Winter and Bradforth, {Stephen E.} and Pavel Jungwirth and Petr Slav{\'i}ček", year = "2012", month = "11", day = "8", doi = "10.1021/jp306348b", language = "English", volume = "116", pages = "13254--13264", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "44", }
@article{326965fef813482690531f9b1649f4c0, title = "Block copolymer lithography: Feature size control and extension by an over-etch technique", abstract = "Block copolymer lithography based on block copolymer (BCP) self-assembly can be used to develop soft mask nanoscale templates for subsequent pattern transfer to generate substrate features. Self-assembly of lamellar polystyrene-b-polymethylmethacrylate BCP of varying molecular weights to generate silicon nanoscale features is reported here. It has also been demonstrated that the feature size can be controlled by a plasma over-etch process and discussed.", keywords = "Block copolymer, Lithography, Over-etching, Plasma etching, Polystyrene-b-polymethylmethacrylate, Self-assembly, Silicon nanowires", author = "Sozaraj Rasappa and Dipu Borah and Ramsankar Senthamaraikannan and Faulkner, {Colm C.} and Shaw, {Matthew T.} and Peter Gleeson and Holmes, {Justin D.} and Morris, {Michael A.}", year = "2012", month = "11", day = "1", doi = "10.1016/j.tsf.2012.09.017", language = "English", volume = "522", pages = "318--323", journal = "Thin Solid Films", issn = "0040-6090", publisher = "Elsevier", }
@article{0b41af3408b8481984b195f2ca9a1bfc, title = "Azobenzene photomechanics: Prospects and potential applications", abstract = "The change in shape inducible in some photo-reversible molecules using light can effect powerful changes to a variety of properties of a host material. This class of reversible light-switchable molecules includes molecules that photodimerize, such as coumarins and anthracenes; those that allow intra-molecular photo-induced bond formation, such as fulgides, spiro-pyrans, and diarylethenes; and those that exhibit photo-isomerization, such as stilbenes, crowded alkenes, and azobenzenes. The most ubiquitous natural molecule for reversible shape change, however, and perhaps the inspiration for all artificial bio-mimics, is the rhodopsin/retinal protein system that enables vision, and this is the quintessential reversible photo-switch for performance and robustness. Here, the small retinal molecule embedded in a cage of rhodopsin helices isomerizes from a cis geometry to a trans geometry around a C=C double bond with the absorption of just a single photon. The modest shape change of just a few angstroms is quickly amplified and sets off a cascade of larger shape and chemical changes, eventually culminating in an electrical signal to the brain of a vision event, the energy of the input photon amplified many thousands of times in the process. Complicated biochemical pathways then revert the trans isomer back to cis, and set the system back up for another cascade upon subsequent absorption. The reversibility is complete, and many subsequent cycles are possible. The reversion mechanism back to the initial cis state is complex and enzymatic, hence direct application of the retinal/rhodopsin photo-switch to engineering systems is difficult. Perhaps the best artificial mimic of this strong photo-switching effect however in terms of reversibility, speed, and simplicity of incorporation, is azobenzene. Trans and cis states can be switched in microseconds with low-power light, reversibility of 10 5 and 10 6 cycles is routine before chemical fatigue, and a wide variety of molecular architectures is available to the synthetic materials chemist, permitting facile anchoring and compatibility, as well as chemical and physical amplification of the simple geometric change. This review article focuses on photo-mechanical effect taking place in various material systems incorporating azobenzene. The photo-mechanical effect can be defined as reversible change in shape by absorption of light, which results in a significant macroscopic mechanical deformation, and reversible mechanical actuation, of the host material. Thus, we exclude simple thermal expansion effects, reversible but non-mechanical photo-switching or photo-chemistry, as well as the wide range of optical and electro-optical switching effects for which good reviews exist elsewhere. Azobenzene-based material systems are also of great interest for light energy harvesting applications across much of the solar spectrum, yet this emerging field is still in an early enough stage of research output as to not yet warrant review, but we hope that some of the ideas put forward here toward promising future directions of research, will help guide the field.", keywords = "Azobenzene, Light harvesting, Liquid crystals, Photochemistry, Photomechanics, Thin films", author = "Zahid Mahimwalla and Yager, {Kevin G.} and Mamiya, {Jun Ichi} and Atsushi Shishido and Arri Priimagi and Barrett, {Christopher J.}", year = "2012", month = "11", doi = "10.1007/s00289-012-0792-0", language = "English", volume = "69", pages = "967--1006", journal = "Polymer Bulletin", issn = "0170-0839", publisher = "Springer Verlag", number = "8", }
@article{61f880bcb7264d7eb7c4d9a68b489769, title = "Influence of ionic liquids on the dielectric relaxation behavior of CNT based elastomer nanocomposites", abstract = "The influence of an imidazolium type ionic liquid (IL) on the relaxation behavior of carbon-nanotube (CNT) based polychloroprene nanocomposites prepared by melt mixing has been investigated by broadband dielectric spectroscopy. It is demonstrated that the presence of the ionic liquid modifies the relaxation behavior of the pure rubber matrix and leads to a significant increase of the conductivity for the CNT/rubber composites. For the unfilled rubber, a distinct glass transition of the IL is observed for high concentrations demonstrating that the IL forms a separate phase. The increased conductivity of the CNT-filled rubber composites is related to a physical coupling between CNTs and rubber matrix mediated by IL leading to a better dispersion of the CNTs.", keywords = "Dielectric spectroscopy, Ionic liquid, Nanocomposites, Relaxation dynamics, Rubber", author = "D. Steinhauser and K. Subramaniam and A. Das and G. Heinrich and M. Kl{\"u}ppel", year = "2012", month = "11", doi = "10.3144/expresspolymlett.2012.98", language = "English", volume = "6", pages = "927--936", journal = "Express Polymer Letters", issn = "1788-618X", publisher = "BME-PT and GTE", number = "11", }
@article{b2fe5be638fd403b903643378a3b24d7, title = "Biomimetic surface modification of polycarbonateurethane film via phosphorylcholine-graft for resisting platelet adhesion", abstract = "Phosphorylcholine groups were covalently introduced onto a polycarbonateurethane (PCU) surface in order to create a biomimetic structure on the polymer surfaces. After introducing primary amine groups onto the polymer surface by 1,6-hexanediamine, phosphorylcholine groups were covalently linked onto the surface by the reductive amination between the amino group and the aldehyde group of phosphorylcholine glyceraldehyde (PCGA). The results of water contact angle test, X-ray photoelectron spectroscopy (XPS), and X-ray fluorescence spectrometer (XRF) analysis of the modified films indicated that PCGA had already been covalently linked to the PCU surface. The topographies and surface roughnesses were both imaged and measured by atomic force microscopy (AFM). Scanning electron microscopy (SEM) observation of the PCU films after treatment with platelet-rich plasma demonstrated that platelets had rarely adhered to the surface of the PCGA-grafted PCU films but had mainly adhered to the surface of the blank PCU films. The platelet adhesion result indicated that the PC modified PCU films could resist platelet adhesion after grafting with PCGA, and that these PCGA-grafted PCU materials, potentially, might be applied as blood-contacting materials.", keywords = "Biomimetic, Phosphorylcholine glyceraldehydes, Platelet adhesion, Polycarbonateurethane, Surface modification", author = "Wei Gao and Yakai Feng and Jian Lu and Musammir Khan and Jintang Guo", year = "2012", month = "10", doi = "10.1007/s13233-012-0152-9", language = "English", volume = "20", pages = "1063--1069", journal = "Macromolecular Research", issn = "1598-5032", publisher = "Springer Verlag", number = "10", }
@article{a65e0477ddf541d2b61f60804c4b4d7f, title = "Effect of sol-gel derived in situ silica on the morphology and mechanical behavior of natural rubber and acrylonitrile butadiene rubber blends", abstract = "Silica particles were generated and grown in situ by sol-gel method into rubber blends comprised of natural rubber (NR) and acrylonitrile butadiene rubber (NBR) at various blend ratios. Silica formed into rubber matrix was amorphous in nature. Amount of in situ silica increased with increase in natural rubber proportion in the blends during the sol-gel process. Morphology studies showed that the generated in situ silica were nanoparticles of different shapes and sizes mostly grown into the NR phase of the blends. In situ silica filled NR/NBR blend composites showed improvement in the mechanical and dynamic mechanical behaviors in comparison to those of the unfilled and externally filled NR/ NBR blend composites. For the NR/NBR blend at 40/60 composition, in particular, the improvement was appreciable where size and dispersion of the silica particles into the rubber matrix were found to be more uniform. Dynamic mechanical analysis revealed a strong rubber-in situ silica interaction as indicated by a positive shift of the glass transition temperature of both the rubber phases in the blends.", keywords = "In situ silica, Reinforcement, Rubber blend, Rubber-filler interaction, Sol-gel", author = "Kapgate, {Bharat P.} and Chayan Das and Amit Das and Debdipta Basu and Uta Reuter and Gert Heinrich", year = "2012", month = "9", doi = "10.1007/s10971-012-2812-9", language = "English", volume = "63", pages = "501--509", journal = "JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY", issn = "0928-0707", publisher = "Springer Verlag", number = "3", }
@article{e687000694f34a8798909481499265eb, title = "Cysteine-tagged chimeric avidin forms high binding capacity layers directly on gold", abstract = "Cysteine-tagged, genetically engineered avidin named ChiAvd-Cys and wild-type avidin form monolayers or bilayer structures when immobilised directly on gold. Non-specific binding can be reduced by a post-treatment of the avidin layers with a N-[tris(hydroxymethyl)methyl]-acrylamide (pTHMMAA) polymer. ChiAvd-Cys showed excellent activity when immobilised on gold. About 70{\%} of the ChiAvd-Cys molecules were able to bind two biotinylated green fluorescent proteins (per avidin tetramer). Amino-biotinylated antibody F(ab′) 2 fragments could be bound to every 4th and 8th ChiAvd-Cys and wild-type avidin molecule, respectively, whereas on average one thiol-biotinylated antibody Fab′-fragment was bound to every ChiAvd-Cys. Antigen binding to the thiol-biotinylated Fab′-fragment bound to the ChiAvd-Cys/pTHMMAA layer was almost twice compared to that of the amino-biotinylated F(ab′) 2-fragments. The high antigen binding was due to a site-directed orientation of the thiol-biotinylated fragments. The ChiAvd-Cys/pTHMMAA layers offer high capacity that may be used to couple biotinylated compounds on biosensor surfaces.", keywords = "Avidin, Biotin, Cysteine tagged, Non-specific binding, Self-assembled monolayer", author = "Inger Vikholm-Lundin and Sanna Auer and Maija Paakkunainen and M{\"a}{\"a}tt{\"a}, {Juha A E} and Tony Munter and Jenni Leppiniemi and Hyt{\"o}nen, {Vesa P.} and Kirsi Tappura", year = "2012", month = "8", doi = "10.1016/j.snb.2012.05.008", language = "English", volume = "171-172", pages = "440--448", journal = "Sensors and Actuators B: Chemical", issn = "0925-4005", publisher = "Elsevier Science", }
@article{2c01c685d5c1490dbefbb22ba9330c8b, title = "Accurate description of aqueous carbonate ions: An effective polarization model verified by neutron scattering", abstract = "The carbonate ion plays a central role in the biochemical formation of the shells of aquatic life, which is an important path for carbon dioxide sequestration. Given the vital role of carbonate in this and other contexts, it is imperative to develop accurate models for such a high charge density ion. As a divalent ion, carbonate has a strong polarizing effect on surrounding water molecules. This raises the question whether it is possible to describe accurately such systems without including polarization. It has recently been suggested the lack of electronic polarization in nonpolarizable water models can be effectively compensated by introducing an electronic dielectric continuum, which is with respect to the forces between atoms equivalent to rescaling the ionic charges. Given how widely nonpolarizable models are used to model electrolyte solutions, establishing the experimental validity of this suggestion is imperative. Here, we examine a stringent test for such models: a comparison of the difference of the neutron scattering structure factors of K 2CO3 vs KNO3 solutions and that predicted by molecular dynamics simulations for various models of the same systems. We compare standard nonpolarizable simulations in SPC/E water to analogous simulations with effective ion charges, as well as simulations in explicitly polarizable POL3 water (which, however, has only about half the experimental polarizability). It is found that the simulation with rescaled charges is in a very good agreement with the experimental data, which is significantly better than for the nonpolarizable simulation and even better than for the explicitly polarizable POL3 model.", author = "Mason, {Philip E.} and Erik Wernersson and Pavel Jungwirth", year = "2012", month = "7", day = "19", doi = "10.1021/jp3008267", language = "English", volume = "116", pages = "8145--8153", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "28", }
@article{b58086f7ba9b4fe1b687744ae8324e85, title = "Highly conducting polychloroprene composites based on multi-walled carbon nanotubes and 1-butyl 3-methyl imidazolium bis(trifluoromethylsulphonyl)imide", abstract = "Highly conducting flexible polychloroprene composites are prepared based on a novel mixing technique using ionic liquid (IL) modified multi-walled carbon nanotubes (MWCNTs). A conductivity of 0.1 S/cm is achieved for composites even at a low concentration of the tubes (5 phr). Extremely fine dispersion and a strong tube-tube networking of modified carbon nanotubes (M-CNTs), which are responsible for such high conductivity of the composites, are understood from transmission electron microscopy and amplitude sweep measurements. Several interesting applications can be visualised using these conducting composites: as a substrate for electronic circuits, and as an excellent construction material.", author = "Kalaivani Subramaniam and Amit Das and Gert Heinrich", year = "2012", month = "7", language = "English", volume = "65", pages = "44--46", journal = "KGK: KAUTSCHUK GUMMI KUNSTSTOFFE", issn = "0948-3276", publisher = "Huthig GmbH", number = "7-8", }
@article{102bc5343f234dd3926727b3e5a2ebc9, title = "Behavior of 4-hydroxynonenal in phospholipid membranes", abstract = "Under conditions of oxidative stress, 4-hydroxy-2-nonenal (4-HNE) is commonly present in vivo. This highly reactive and cytotoxic compound is generated by oxidation of lipids in membranes and can be easily transferred from a membrane to both cytosol and the extracellular space. Employing time-dependent fluorescence shift (TDFS) method and molecular dynamics simulations, we found that 4-HNE is stabilized in the carbonyl region of a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) bilayer. 4-HNE is thus able to react with cell membrane proteins and lipids. Stabilization in the membrane is, however, moderate and a transfer of 4-HNE to either extra- or intracellular space occurs on a microsecond time scale. These molecular-level details of 4-HNE behavior in the lipid membrane rationalize the experimentally observed reactivity of 4-HNE with proteins inside and outside the cell. Furthermore, these results support the view that 4-HNE may play an active role in cell signaling pathways.", author = "Mario Vazdar and Piotr Jurkiewicz and Martin Hof and Pavel Jungwirth and Lukasz Cwiklik", year = "2012", month = "6", day = "7", doi = "10.1021/jp3044219", language = "English", volume = "116", pages = "6411--6415", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "22", }
@article{7584ecb4f9dd48c1aeea20dd9490e7fd, title = "Enhanced thermal stability of polychloroprene rubber composites with ionic liquid modified MWCNTs", abstract = "Thermal degradation of polychloroprene rubber (CR) composites based on unmodified and ionic liquid modified multi-walled carbon nanotubes (MWCNTs) is studied using thermogravimetric analysis (TGA) in aerobic and anaerobic (nitrogen) conditions. The CR and its composites exhibit three stage and four stage degradation in nitrogen and air respectively. The presence of unmodified CNTs alone does not improve the thermal stability of composites to a great extent whereas a reasonable enhancement is observed in case of modified CNTs/CR composites which can be attributed to the interfacial interactions of ionic liquid/modified tubes with CR and to the fine dispersion of modified tubes in CR. The degradation products of CR and its composites were analysed using pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) and the mechanism of degradation is discussed. Non-isothermal degradation kinetics were studied using Kissinger and Flynn-Wall-Ozawa methods and the activation energy of thermal decomposition is found to be high for modified CNTs/CR composites. Isothermal degradation of modified CNTs/CR composites at 290°C for 30 min in nitrogen reveals decreased weight loss (14{\%}) as opposed to CR (31{\%}) and unmodified CNTs/CR composites (30{\%}). The combustion behaviour of the composites was dealt using microscale combustion calorimeter (MCC) and the flame retardancy of the composites is discussed.", keywords = "Carbon nanotubes, Elastomeric composites, Ionic liquids, Polychloroprene rubber, Thermal degradation, Thermal stability", author = "Kalaivani Subramaniam and Amit Das and Liane H{\"a}u{\ss}ler and Christina Harnisch and St{\"o}ckelhuber, {Klaus Werner} and Gert Heinrich", year = "2012", month = "5", doi = "10.1016/j.polymdegradstab.2012.02.001", language = "English", volume = "97", pages = "776--785", journal = "Polymer Degradation and Stability", issn = "0141-3910", publisher = "Elsevier", number = "5", }
@article{332be738d79448aea97b04b6e8367aed, title = "Highly exfoliated natural rubber/Clay composites by {"}propping-open procedure{"}: The influence of fatty-acid chain length on exfoliation", abstract = "A high degree of exfoliation of MMT in NR is achieved by using the so-called {"}propping-open approach{"} in which a stepwise expansion of the interlayer spacing of MMT takes place. The nanostructure is characterized by WAXD and TEM which indicate different extents of clay dispersion depending on the fatty-acid chain length. Curing kinetics of different nanocomposites is studied and interestingly low activation energies of the vulcanization process are observed in the case of NR/EMMT nanocomposites. The incorporation of EMMT dramatically affects composite properties whereas DMA indicates significant reduction of tan δ peak height and the tensile strength approximately doubles from 14 to 30 MPa with only 5 phr EMMT.", keywords = "curing kinetics, exfoliation, Mooney-Rivlin equation, nanocomposites, propping-open approach", author = "Sandip Rooj and Amit Das and St{\"o}ckelhuber, {Klaus Werner} and Uta Reuter and Gert Heinrich", year = "2012", month = "4", doi = "10.1002/mame.201100185", language = "English", volume = "297", pages = "369--383", journal = "Macromolecular Materials and Engineering", issn = "1438-7492", publisher = "WILEY-V C H VERLAG GMBH", number = "4", }
@article{f1240ba9778148059475cbbf8ccb01dc, title = "A novel thermotropic elastomer based on highly-filled LDH-SSB composites", abstract = "Elastomeric composites are prepared based on solution styrene butadiene elastomer and zinc-aluminium layered double hydroxides (LDH), using a conventional sulphur cure system. Up to 100 parts per hundred rubber of LDH are incorporated into the elastomer matrix. The composites exhibit an interesting phenomenon of thermoreversible transparency, i.e. the transparent sample becomes opaque at warm condition and restores the transparency at room temperature. The transparency is found to be increased as the amount of LDH was increased. The addition of LDH gradually improved the mechanical, dynamic mechanical performance and thermal stability of the base elastomer. These developped elastomers could be utilised as smart materials in different applications", author = "Amit Das and George, {Jinu Jacob} and Burak Kutlu and Andreas Leuteritz and Wang, {De Yi} and Sandip Rooj and Ren{\'e} Jurk and Ramanujam Rajeshbabu and St{\"o}ckelhuber, {Klaus Werner} and Vassilios Galiatsatos and Gert Heinrich", year = "2012", month = "2", day = "27", doi = "10.1002/marc.201100735", language = "English", volume = "33", pages = "337--342", journal = "Macromolecular Rapid Communications", issn = "1022-1336", publisher = "Wiley-VCH Verlag", number = "4", }
@article{fe222525b3274cafb54cc29780cf84a1, title = "Crystallization mechanism of the bioactive glasses, 45S5 and S53P4", abstract = "The crystallization kinetics of the two commercial bioactive glasses, 45S5 and S53P4, was studied using differential thermal analysis (DTA), optical microscopy, and scanning electron microscopy (SEM). The thermal properties, the activation energy of crystallization, and the Johnson-Mehl-Avrami (JMA) exponent were determined for two glass fractions: fine powder (2content. The nucleation temperature range of these two glasses together with DTA data makes it possible to develop guidelines for tailoring thermal treatment parameters to achieve desired glass-to-crystal ratios.", author = "Jonathan Massera and Susanne Fagerlund and Leena Hupa and Mikko Hupa", year = "2012", month = "2", doi = "10.1111/j.1551-2916.2011.05012.x", language = "English", volume = "95", pages = "607--613", journal = "JOURNAL OF THE AMERICAN CERAMIC SOCIETY", issn = "0002-7820", publisher = "Wiley", number = "2", }
@article{babb1401985b4a188e127b345438e67d, title = "Printable and flexible macroporous organosilica film with high protein adsorption capacity", abstract = "An approach for creating a flexible and macroporous silsesquioxane film using phase separation method is described. The porous film was prepared by a simple coating method where sol-gel solution containing polyacrylic acid (PAA) and 1,6-bis(trimethoxysilyl)hexane in water was applied on boehmite silica coated polymethylmethacrylate (PMMA) film. After drying, the water soluble PAA template was removed by washing the film with water revealing the porous film. With certain ratios of PAA and water, fully co-continuous pore system with open surface was obtained. Porous films with 3-4 μm thickness were found to be highly flexible. The biocompatibility of the porous film was tested by immobilizing a high affinity biotin-binding chimeric avidin (ChiAVD(I117Y)) into the porous matrix The porous film was found to adsorb higher amounts of functional chimeric avidin compared to the pure PMMA film or a boehmite silica coated PMMA film.", keywords = "Flexible coatings, Phase separation, Porous films, Printable coatings, Protein immobilization, Sol-gel", author = "Heikkinen, {Jarkko J.} and Liisa Kivim{\"a}ki and Hyt{\"o}nen, {Vesa P.} and Kulomaa, {Markku S.} and Hormi, {Osmo E O}", year = "2012", month = "1", day = "1", doi = "10.1016/j.tsf.2011.09.041", language = "English", volume = "520", pages = "1934--1937", journal = "Thin Solid Films", issn = "0040-6090", publisher = "Elsevier", number = "6", }
@inproceedings{d947761bd76e4f7e9ce94af68cd039b7, title = "HVOF process control enabling strategies", abstract = "Complexity in dynamics and mechanism of supersonic flame formation and effects of processing variables has made the understanding of interaction of particles and flame a difficult task. Lack of such understanding limits the possibilities of controlling the process to obtain desired in-flight particles temperature and velocity and consequent particles state. This problem is even more pronounced in TS systems with no dedicated decoupled temperature and velocity controlled regime. Different approaches based on total volume flow, back pressure and fuel to oxygen ratio have been examined to address the robustness of each approach to control the temperature and velocity. WC-CoCr material was used employing DJ-2600 torch. A guideline to control the in-flight particles temperature and velocity based on process variables is provided. A process map was developed to establish a correlation between process, in-flight particles state, microstructure, properties and performance.", author = "A. Ghabchi and T. Varis and K. Holmberg and S. Sampath", year = "2012", language = "English", isbn = "9781632666796", pages = "465--471", booktitle = "International Thermal Spray Conference and Exposition, ITSC 2012 - Air, Land, Water and the Human Body: Thermal Spray Science and Applications", publisher = "ASM International", address = "United States", }
@article{dbd1e3e5d62e4de3af5569b1504eb165, title = "Location of the Azobenzene moieties within the cross-linked liquid-crystalline polymers can dictate the direction of photoinduced bending", abstract = "We present a simple way to control the photoinduced bending direction of azobenzene-containing cross-linked liquidcrystalline polymers. By changing the location of the photoactive azobenzene moieties from cross-links to side-chains, the bending direction of the sample is reversed under identical irradiation conditions. In addition to providing a versatile route toward directionality control of the photoinduced macroscopic motions, this observation highlights the complicated nature of the photomechanical response of azobenzene-containing cross-linked liquidcrystalline polymers, showing that the photomobile behavior can be determined by seemingly small details on the materials design.", author = "Arri Priimagi and Aki Shimamura and Mizuho Kondo and Tomohiro Hiraoka and Shoichi Kubo and Mamiya, {Jun Ichi} and Motoi Kinoshita and Tomiki Ikeda and Atsushi Shishido", year = "2012", doi = "10.1021/mz200056w", language = "English", volume = "1", pages = "96--99", journal = "ACS Macro Letters", issn = "2161-1653", publisher = "American Chemical Society ACS", number = "1", }
@article{0ffebe64478b4c4c9f7f49220b138296, title = "Orientational dependence of the affinity of guanidinium ions to the water surface", abstract = "The behavior of guanidinium chloride at the surface of aqueous solutions is investigated using classical molecular dynamics (MD) simulations. It is found that the population of guanidinium ions oriented parallel to the interface is greater in the surface region than in bulk. The opposite is true for ions in other orientations. Overall, guanidinium chloride is depleted in the surface region, in agreement with the fact that the addition of guanidinium chloride increases the surface tension of water. The orientational dependence of the surface affinity of the guanidinium cation is related to its anisotropic hydration. To bring the ion to the surface in the parallel orientation does not require hydrogen bonds to be broken, in contrast to other orientations. The surface enrichment of parallel-oriented guanidinium indicates that its solvation is more favorable near the surface than in bulk solution for this orientation. The dependence of the bulk and surface properties of guanidinium on the force field parameters is also investigated. Despite significant quantitative differences between the force fields, the surface behavior is qualitatively robust. The implications for the orientations of the guanidinium groups of arginine side chains on protein surfaces are also outlined.", author = "Erik Wernersson and Jan Heyda and Mario Vazdar and Mikael Lund and Mason, {Philip E.} and Pavel Jungwirth", year = "2011", month = "11", day = "3", doi = "10.1021/jp207499s", language = "English", volume = "115", pages = "12521--12526", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "43", }
@article{ae79704fc94741bc91b2822cced89c98, title = "Efficient surface structuring and photoalignment of supramolecular polymer-azobenzene complexes through rational chromophore design", abstract = "Rational selection of the para-substituent of azobenzene chromophores in supramolecular polymeric complexes is exploited to control the chromophore-chromophore intermolecular interactions occurring in the material system. This allows optimizing the material system for either efficient surface-relief formation or for high and stable photoalignment. The surface-relief gratings can be subsequently coated with amorphous TiO 2 using atomic layer deposition, resulting in high-quality and high-index organic-inorganic gratings with vastly improved thermal stability compared to all-polymeric gratings.", author = "Jaana Vapaavuori and Ville Valtavirta and Tapani Alasaarela and Mamiya, {Jun Ichi} and Arri Priimagi and Atsushi Shishido and Matti Kaivola", year = "2011", month = "10", day = "21", doi = "10.1039/c1jm12642c", language = "English", volume = "21", pages = "15437--15441", journal = "Journal of Materials Chemistry", issn = "0959-9428", publisher = "ROYAL SOC CHEMISTRY", number = "39", }
@article{fe9fa299bb2945119c570ab7edf1584b, title = "Thermally evaporated single-crystal Germanium on Silicon", abstract = "Using conventional and polarization-dependent Raman spectroscopy we investigate the structural properties of Germanium films thermally evaporated on Silicon under various conditions. The analysis suggests that the Ge films can be crystalline, amorphous and poly-oriented, depending on the substrate temperature. We use both comparison with Raman spectra of Ge films grown on amorphous substrates and polarization-dependent Raman measurements to demonstrate that in the 250-450 °C interval, crystalline Ge films are epitaxial. This result is validated by means of large angle X-ray diffraction measurements. We employ these films to fabricate and characterize near infrared heterojunction photodiodes that exhibit high responsivities and low dark current densities.", keywords = "Germanium, Near infrared, Photodetectors, Raman characterization, Thermal evaporation", author = "V. Sorianello and L. Colace and M. Nardone and G. Assanto", year = "2011", month = "9", day = "1", doi = "10.1016/j.tsf.2011.06.023", language = "English", volume = "519", pages = "8037--8040", journal = "Thin Solid Films", issn = "0040-6090", publisher = "Elsevier", number = "22", }
@article{a4784837b7f54094bab4f6c89e37e247, title = "Towards universal enrichment nanocoating for IR-ATR waveguides", abstract = "Polymer multilayered nanocoating capable of concentrating various chemical substances at IR-ATR waveguide surfaces is described. The coating affinity to an analyte played a pivotal role in sensitivity enhancement of the IR-ATR measurements, since the unmodified waveguide did not show any analyte detection.", author = "James Giammarco and Bogdan Zdyrko and Laeticia Petit and Musgraves, {J. David} and Juejun Hu and Anu Agarwal and Lionel Kimerling and Kathleen Richardson and Igor Luzinov", year = "2011", month = "8", day = "28", doi = "10.1039/c1cc12780b", language = "English", volume = "47", pages = "9104--9106", journal = "Chemical Communications", issn = "1359-7345", publisher = "ROYAL SOC CHEMISTRY", number = "32", }
@article{f633cc82887b45bcb983913821b69dbd, title = "Detection of 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) by displacement of antibodies", abstract = "A molecular layer with low non-specific binding enabling determination of low concentrations of 3,4-methylenedioxymethamphetamine (MDMA) by the displacement of antibodies has been developed. Antibody Fab′-fragments at various concentrations have been site-directly immobilised on gold and intercalated with a hydrophilic non-ionic polymer that reduces non-specific binding. Bovine serum albumin conjugated with MDMA and various concentrations of anti-MDMA antibodies were bound to the layer. The amount of conjugates and antibodies bound was dependent on the amount of Fab′-fragments in the layer. Antibodies were also bound to the conjugates physisorbed directly onto the gold surface and in mixtures with the polymer or with a lipoamide. A high displacement of antibodies was observed by surface plasmon resonance (SPR) on interaction of MDMA with the different layers in buffer solution. No displacement could, however, be observed in saliva with the pure conjugate layer because of a high non-specific binding of proteins. When the conjugates were coupled to the surface through the antibody Fab-fragment/polymer layer, MDMA concentrations as low as 0.02 ng mL-1 (0.14 nM) could easily be detected in buffer. In diluted saliva the lowest limit of detection was 0.4 ng mL-1 enabling determination of drugs from saliva with a cut-off concentration of 2 ng mL-1. The molecular layer of antibody Fab′-fragments and polymer thus shows great potential for binding conjugates and antibodies that can be displaced on the interaction with very low concentrations of small-sized molecules. A low non-specific binding is guaranteed by the presence of the hydrophilic polymer.", keywords = "Antibody displacement, Drugs of abuse, Ecstasy, Immobilisation, MDMA, Surface plasmon resonance", author = "Inger Vikholm-Lundin and Sanna Auer and Hellgren, {Ann Charlotte}", year = "2011", month = "8", day = "10", doi = "10.1016/j.snb.2011.03.069", language = "English", volume = "156", pages = "28--34", journal = "Sensors and Actuators B: Chemical", issn = "0925-4005", publisher = "Elsevier Science", number = "1", }
@article{94868fa2e86c4f0fb51e8ecdea94cbae, title = "Urea and guanidinium induced denaturation of a Trp-cage miniprotein", abstract = "Using a combination of experimental techniques (circular dichroism, differential scanning calorimetry, and NMR) and molecular dynamics simulations, we performed an extensive study of denaturation of the Trp-cage miniprotein by urea and guanidinium. The experiments, despite their different sensitivities to various aspects of the denaturation process, consistently point to simple, two-state unfolding process. Microsecond molecular dynamics simulations with a femtosecond time resolution allow us to unravel the detailed molecular mechanism of Trp-cage unfolding. The process starts with a destabilizing proline shift in the hydrophobic core of the miniprotein, followed by a gradual destruction of the hydrophobic loop and the α-helix. Despite differences in interactions of urea vs guanidinium with various peptide moieties, the overall destabilizing action of these two denaturants on Trp-cage is very similar.", author = "Jan Heyda and Milan Kož{\'i}šek and Lucie Bedn{\'a}rova and Gary Thompson and Jan Konvalinka and Jiř{\'i} Vondr{\'a}šek and Pavel Jungwirth", year = "2011", month = "7", day = "21", doi = "10.1021/jp200790h", language = "English", volume = "115", pages = "8910--8924", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "28", }
@article{a964420924344d4ea580d6c8d951613d, title = "Hybrid nanoparticle design based on cationized gelatin and the polyanions dextran sulfate and chondroitin sulfate for ocular gene therapy", abstract = "We describe the development of hybrid nanoparticles composed of cationized gelatin and the polyanions CS and DS for gene therapy in the ocular surface. The physicochemical properties of the nanoparticles that impact their bioperformance, such as average size and zeta potential, can be conveniently modulated by changing the ratio of polymers and the crosslinker. These systems associate plasmid DNA and are able to protect it from DNase I degradation. We corroborate that the introduction of CS or DS in the formulation decreases the in vitro toxicity of the nanoparticles to human corneal cells without compromising the transfection efficiency. These nanoparticles are potential candidates for the development of safer and more effective nanomedicines for ocular therapy. New hybrid nanoparticles composed of cationized gelatin and natural polyanions are developed and characterized. The incorporation of chondroitin sulfate or dextran sulfate in cationized gelatin nanoparticles decreases their toxicity while preserving their transfection efficiency in human corneal cells. These nanoparticles are potential candidates for the development of safer and more effective nanomedicines for ocular therapy.", keywords = "Drug delivery systems, Gelation, Nanoparticles, Nanotechnology", author = "Zorzi, {Giovanni Konat} and P{\'a}rraga, {Jenny Evelin} and Bego{\~n}a Seijo and Alejandro S{\'a}nchez", year = "2011", month = "7", day = "7", doi = "10.1002/mabi.201100005", language = "English", volume = "11", pages = "905--913", journal = "MACROMOLECULAR BIOSCIENCE", issn = "1616-5187", publisher = "Wiley-VCH Verlag", number = "7", }
@article{7b5648d6302646e3b3f598a6fffc0285, title = "Optimised selection of new protective coatings for biofuel boiler applications", abstract = "Using biofuels in power and CHP boilers can pose a challenge for materials performance. Formation of deposits containing e.g. potassium, sulphur, calcium, sodium, and chlorine can result in severe corrosion of conventional steels and alloys at relatively modest temperatures. Given suitable component design and fabrication facilities, coatings may be considered to protect the fireside surfaces. This paper aims to present a systematic approach to the design and selection criteria for protective coatings of boilers. The approach includes modelling of the process and surface conditions, optimisation of the coating process and structure, and performance validation in the laboratory and plant scales. The applied examples have included iron and nickel based HVOF and arc sprayed coatings subjected to verification field testing in boiler testing under aggressive biofuel conditions. The coatings have shown good corrosion resistance in both laboratory tests and long-term harsh field tests. The paper discusses the used approach for finding a suitable and cost effective coating for biofuel boiler applications. The paper gives test results from microstructural, corrosion resistance and field testing experience for the selected coatings.", keywords = "biofuel boiler, coating performance, life extension, protection", author = "S. Tuurna and T. Varis and K. Penttil{\"a} and K. Ruusuvuori and S. Holmstr{\"o}m and S. Yli-Olli", year = "2011", month = "7", doi = "10.1002/maco.201005898", language = "English", volume = "62", pages = "642--649", journal = "Materials and Corrosion-Werkstoffe und Korrosion", issn = "0947-5117", publisher = "Wiley-VCH Verlag", number = "7", }
@article{150e415388544e189ddea5a7394f3fb8, title = "Preparation of zinc oxide free, transparent rubber nanocomposites using a layered double hydroxide filler", abstract = "A layered double hydroxide (LDH) mineral filler particle has been designed and employed in rubber vulcanization to prepare a more environmentally friendly rubber composite. The LDH delivers zinc ions in the vulcanization process as accelerators, stearate anions as activators and simultaneously the mineral sheets act as a nanofiller to reinforce the rubber matrix whilst totally replacing the separate zinc oxide (ZnO) and stearic acid conventionally used in the formulation of rubber. This method leads to a significant reduction (nearly 10 times) of the zinc level and yields excellent transparent properties in the final rubber product. The morphological characterization, rheometric curing behaviour, mechanical properties and uniaxial multi-hysteresis behaviours of the resultant rubber/LDH nanocomposite are studied in this paper.", author = "Amit Das and Wang, {De Yi} and Andreas Leuteritz and Kalaivani Subramaniam and Greenwell, {H. Chris} and Udo Wagenknecht and Gert Heinrich", year = "2011", month = "5", day = "28", doi = "10.1039/c0jm03784b", language = "English", volume = "21", pages = "7194--7200", journal = "Journal of Materials Chemistry", issn = "0959-9428", publisher = "ROYAL SOC CHEMISTRY", number = "20", }
@article{4d3c4d6615c24d4b98e2c8da1b540aae, title = "Energetic origin of proton affinity to the air/water interface", abstract = "Recent experimental and theoretical studies showed the preference of the hydronium ion for the vapor/water interface. To investigate the mechanism responsible for the surface propensity of this ion, we performed a series of novel quantum chemical simulations combined with the theory of solutions. The solvation free energy of the H3O+ solute placed at the interface was obtained as -97.9 kcal/mol, being more stable by 3.6 kcal/mol than that of the solute embedded in the bulk. Further, we decomposed the solvation free energies into contributions from the water molecules residing in the oxygen and the hydrogen sides of the solute to clarify the origin of the surface preference. When the solute was displaced from the bulk to the interface, it was shown that the free energy contribution from the oxygen side is destabilized by ∼10 kcal/mol because of a reduction of the number of surrounding solvent water molecules. It was observed, however, that the free energy contribution due to the hydrogen side of the solute is unexpectedly stabilizing and surpasses the destabilization in the opposite side. We found that the stabilization in the hydrogen side originates from the solute-solvent interaction in the medium range beyond the nearest neighbor. It was also revealed that the free energy contribution due to the solute's electronic polarization amounts to about the half of the total free energy change associated with the solute displacement from the bulk to the interface.", author = "Hideaki Takahashi and Kunihiro Maruyama and Yasuhito Karino and Akihiro Morita and Masayoshi Nakano and Pavel Jungwirth and Nobuyuki Matubayasi", year = "2011", month = "4", day = "28", doi = "10.1021/jp2015676", language = "English", volume = "115", pages = "4745--4751", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "16", }
@article{9ef99047ae0f42d9972e68323725bf14, title = "Preintercalation of an organic accelerator into nanogalleries and preparation of ethylene propylene diene terpolymer rubber-clay nanocomposites", abstract = "A multifunctional additive, bis(diisopropyl) thiophosphoryl diisopropyl disulfide (DIPDIS), was melted in the presence of quaternary ammonium-modified montmorillonite clay and incorporated into an ethylene propylene diene terpolymer (EPDM) rubber matrix as a nanofiller to prepare EPDM rubber nanocomposites. The finer dispersion of the organoclay (OC) in the rubber matrix was observed when the OC was preintercalated by DIPDIS using the propping-open procedure. X-ray diffraction (XRD) results showed that the silicate layers of the OC were successfully preintercalated by the DIPDIS; that is, the basal spacing of clay galleries was expanded from 2.98 to 3.76 nm. Because of the larger interlayer distance, as evidenced by XRD studies, the delamination process was facilitated through the easy intercalation of macromolecular rubber chains, which was reflected in various properties, such as the stress-strain behavior, thermal stability, dynamic mechanical properties and swelling properties. XRD studies and transmission electron microscopy directly supported the effective filler dispersion in the non-polar EPDM rubber matrix.", keywords = "DIPDIS, montmorillonite, multifunctional additive, propping-open procedure", author = "Sandip Rooj and Amit Das and Gert Heinrich", year = "2011", month = "3", doi = "10.1038/pj.2010.132", language = "English", volume = "43", pages = "285--292", journal = "POLYMER JOURNAL", issn = "0032-3896", publisher = "Nature Publishing Group", number = "3", }
@article{cb38992d9eb94c53abdf4ed39b21f7fb, title = "Ionization of purine tautomers in nucleobases, nucleosides, and nucleotides: From the gas phase to the aqueous environment", abstract = "We have simulated ionization of purine nucleic acid components in the gas phase and in a water environment. The vertical and adiabatic ionization processes were calculated at the PMP2/aug-cc-pVDZ level with the TDDFT method applied to obtain ionization from the deeper lying orbitals. The water environment was modeled via microsolvation approach and using a nonequilibrium polarizable continuum model. We have characterized a set of guanine tautomers and investigated nucleosides and nucleotides in different conformations. The results for guanine, i.e., the nucleic acid base with the lowest vertical ionization potential, were also compared to those for the other purine base, adenine. The main findings of our study are the following: (i) Guanine remains clearly the base with the lowest ionization energy even upon aqueous solvation. (ii) Water solvent has a strong effect on the ionization energetics of guanine and adenine and their derivatives; the vertical ionization potential (VIP) is lowered by about 1 eV for guanine while it is ∼1.5 eV higher in the nucleotides, overall resulting in similar VIPs for GMP-, guanosine and guanine in water. (iii) Water efficiently screens the electrostatic interactions between nucleic acid components. Consequently, ionization in water always originates from the base unit of the nucleic acid and all the information about conformational state is lost in the ionization energetics. (iv) The energy splitting between ionization of the two least bound electrons increases upon solvation. (v) Tautomerism does not contribute to the width of the photoelectron spectra in water. (vi) The effect of specific short-range interactions with individual solvent molecules is negligible for purine bases, compared to the long-range dielectric effects of the aqueous medium.", author = "Eva Pluhařov{\'a} and Pavel Jungwirth and Bradforth, {Stephen E.} and Petr Slav{\'i}ček", year = "2011", month = "2", day = "10", doi = "10.1021/jp110388v", language = "English", volume = "115", pages = "1294--1305", journal = "Journal of Physical Chemistry Part B", issn = "1520-6106", publisher = "American Chemical Society", number = "5", }
@inproceedings{c1ccd4b13acf4bf09cf3a5c9c9385e29, title = "Gas atomized thermal spray powders of various metals and alloys", abstract = "Thermal spraying is a group of methods which are used to produce for example wear and corrosion resistant coatings on different surfaces. Fine powder of material is fed to high temperature gas flow. The particles accelerate, partially melt and hit to the surface to form a coating. Thermal spraying sets some requirements for the powder. The powder should be able to be fed with constant feed rate and the particle size distribution should be quite narrow to achieve even melt fraction of the particles. For metal alloys gas atomization is the optimum method to produce thermal spray powders. In this paper, results of some powders prepared by laboratory scale medium/high pressure gas atomizer are discussed. Motivation of this work was to study if thermal spray powders could be atomized in suitable particle size without major post processing. Copper and different stainless steels were atomized. Characterization of particle size and morphology were tested. Different aspects of atomization and post processing to increase thermal spray powder quality are discussed.", author = "Juha Lagerbom and Tapio Ritvonen and Tomi Suhonen and Tommi Varis", year = "2011", language = "English", isbn = "9781899072200", volume = "2", booktitle = "Proceedings of the Euro International Powder Metallurgy Congress and Exhibition, Euro PM 2011", publisher = "European Powder Metallurgy Association (EPMA)", }
@article{119c0301d2ea46c2a7792e683ac45cf9, title = "Calculated electronic density of states and structural properties of tetrahedral amorphous carbon", abstract = "A series of tetrahedral amorphous carbon structures with different microscopic mass densities was generated by calculations based on the density functional theory with a local density approximation and using a method of melting-cooling cycles. A detailed investigation of the properties of the simulated structures has been carried out. Particularly, the short-range order, nearest neighbour distances, fractions of sp1, sp2 and sp3 sites, average C-C-C bond angles and electronic density of states have been analyzed. The simulated structures and calculated properties are in good agreement with those obtained by others and with the experimental data. An unexpected observation is the presence of planar structures, which are typical for graphite, in the sample with low density. In addition, the nearest neighbour distance in the sample with mass density 3.54 g/cm3 is different from those reported previously. Possibilities to compare the density of states obtained from the simulations with the experimental results from scanning tunnelling spectroscopy and X-ray near edge spectrum are discussed.", author = "Koivusaari, {K. Jarmo} and Rantala, {Tapio T.} and Seppo Lepp{\"a}vuori", year = "2000", month = "4", doi = "10.1016/S0925-9635(99)00286-1", language = "English", volume = "9", pages = "736--740", journal = "Diamond and Related Materials", issn = "0925-9635", publisher = "Elsevier", number = "3", }
@article{ad069624864b4f47b02c6e1a9dc07609, title = "Vacancy-type defect distributions near argon sputtered Al(100) surface studied by variable-energy positrons and molecular dynamics simulations", abstract = "A beam of variable-energy positrons, whose back-diffusion probability is measured as a function of positron implantation energy, is applied to studies of depth distribution of sputtering damage in aluminum. The defects are produced by argon ion bombardment of an Al(110) surface in ultra-high vacuum. We have varied the Ar+ energy, incident angle and dose, as well as sputtering and annealing temperatures. The extracted defect profiles have typically a narrow peak at the surface with a width of 10-20 A and a broader tail extending down to 50-100 {\AA}. The shape of the defect profile varies only slightly with the sputtering energy and angle. Defect production at less than 1 keV Ar+ energies is typically 1-5 vacancies per incident ion. The defect profiles become fluence-independent at about 2 × 1016 Ar+ cm-2. The defect density at the outer atomic layers saturates at high argon fluences to a few at{\%}, depending on sputtering conditions. The sputtering temperature (below or above the vacancy migration stage at 250 K) has little effect on vacancy profiles. Defects anneal out gradually between 100 °C and 400 °C. Sputtering damage was also evaluated with the molecular dynamics technique. The shape and depth scale of the simulated collision cascades are in agreement with the experimentally extracted quantities.", author = "J. M{\"a}kinen and A. Vehanen and P. Hautoj{\"a}rvi and H. Huomo and J. Lahtinen and Nieminen, {R. M.} and S. Valkealahti", year = "1986", month = "9", day = "2", doi = "10.1016/0039-6028(86)90242-6", language = "English", volume = "175", pages = "385--414", journal = "Surcface Science", issn = "0039-6028", publisher = "Elsevier", number = "2", }
@article{926b6695cd554e37b6c24f8e47379383, title = "A Finite Cluster Approach to the Electron-Hole Pair Damping of the Adsorbate Vibration: CO Adsorbed on Cu(100)", abstract = "Abstract: A finite cluster method is applied to describe the energy transfer from the adsorbate vibrations to the electron-hole pair excitations. For CO stretch vibration on Cu(100) surface a value of 0.5 meV is found for the consequent damping (corresponding to the lifetime of 1.3·10 -12 s) in an agreement with a recently measured vibrational line width. The mechanism behind the electron-hole pair excitations is found to be charge oscillations between the molecular 2π * resonance and the substrate, caused by the molecular vibration. Cluster size effects have been found to be negligible.", author = "Rantala, {T. T.} and A. Ros{\'e}n and B. Hellsing", year = "1986", doi = "10.1016/S0167-2991(09)61238-6", language = "English", volume = "26", pages = "173--181", journal = "Studies in Surface Science and Catalysis", issn = "0167-2991", publisher = "Elsevier BV", number = "C", }